Ideal strategy to do research is to have idea and make plan. 

Rajesh You asked "What is the Ideal strategy to do research? What is the specific time constraint for research. For me there's some ambiguity. Are you asking what is the ideal  strategy as reason for research? or the ideal strategy in undertaking it? How much credibility does your project need? Use only learned papers.. The specific time constraint is what you are allowed or critical or crisis point in permitting or preventing 'something' or allocated by your self or your employment duty, other responsibilities  unit duration or your own life expectancy; otherwise you are asking 'how long is a piece of string'.

Mission: Firstly what is your goal?.Is it clear?...if not clarify it. Do an inclusion/exclusion list to set your agenda. Either way, write it down andmould it into simple clarity. . .If at Uni what are the unit data, information, gist and stated goals? Ponder the unit statement and its outline? These set your limits and parameters. With research, are you just exploring? how much time do you have as luxury? With project research are you looking for support? or reality?. Academic research is generally seeking support, Reality  suggests looking at support and opposition Decide how much time you should apportion. It may be as simple as "Clancy (2017) rebuts that proposition'

Pure research towards a specific goal will be open minded but for credibility be  bound by well established and fiercely-defended scientific principles and protocols which will find peer support or discover vicious enemies. Indicators for other important research may unfold as you progress. That may be a lifetime occupation so you strategy should include all-embracing diaries. Need it be said? that an employer might set your time scales.

Time?...as a general rule meet your programme but within it, you or you (alarm) clock will sense whether you are using time effectively. Try not to spread unused time into other steps; keep it for review. 

Policy and resources:You are the person, not us to decide how much time you can allocate to each of the steps which will aid you in climbing towards a decision in which your target is reached by the steps you undertake in reaching it. What resources are sensibly available? What limits are placed upon you or by yourself?. Choose your resources with a time scale in mind and also what strategy, resource and research will gain you the greatest amount of thoroughly-relevant progress in the time allowed or allocated.

It is a strategic mission set goals, allow for inefficiency, move on quickly to your next planned objective. Learn rapidly from your casualty list...wasted time, distractions..

Plan the steps you can take in access to data or information. Always accredit sources...that also helps if you want to return to them. You can spend hours trying to find a resource which just seems not to be re-findable, even using the same search words and engine.

.Do not wasted time in useless endeavours. Decide quickly what is relevant within your parameters....create a time plan for the steps based on complexity and significance in the mission.....as you might for a school exam

Each time you set out to research, reassess and realign your strategy in your head or on paper...don't jump around. .If your research is for a university unit, the conclusions you have to reach determine your time frame. If researching towards cure of a disease the strategy and time will be based on knowing where others 'are' and in collaboration with more expert people who can guide you whether your research has already been done or is pointless. In pure research  where to find what as already been done, what remains to be done in the view of others, how does that fit with your own mission relevant?...irrelevant? or why it is pointless.

In pure research do you now consider you might be best served in following one of the significant areas other have put aside for the moment? It is easy to be distracted owing to interesting or perplexing findings along the way,

Set you mission, decide on your resources, keep clearly connected notes, stay on the track, know when you have achieved your goal. If you do not have time to reach your goal, reduce your mission to a target or landmark along the way and defend that position. If at uni indicate that further research is required and make clear what has been achieved so far...not in spurious matters but between the starting point and your goal. If you see valuable side issues worthy of further investigation state them if they are possibly or clearly relevant to the mission. Remember 

I just wrote an answer but it seems to have disappeared. In the last line  I wanted to say 'Remember your mission'. At the end of it however this writing of yours I found when searching for my response pulled me up. It seems to me to make little sense. I'd be having a good look at organising your thinking and logic at every turn in your research, Identify Mission, decide on the effective course of action and write the steps, clarify and reduce them. . Do not be distracted into useless endeavours. Keep clear diaries which make logical sense.

 Set clarified steps to your goal and amortise your time sensibly over them. Don't repeat already definitive research but rather cite it. If you run out of time stop at a major point,  explain its significance on the path in the strategic mission and clarified goal and concisely what further research you see necessary to achieve your mission.,  I don't want to rewrite the answer I gave again as I have assignments to do. Maybe it will turn up. This is what I say makes no sense in meaning or construction as it stands.:

"As medicinal science heading towards the new discoveries, but the trap of psychological disorders, kept questioning about the capabilities of medicinal science. They sinisterly kill people through their slow poisons like dementia"