Dear Subhash Kumar normally in a published research paper the results are reported in a shorter and more concise way than in a PhD thesis. In the thesis you can describe more details and even mention negative results. In any case a published paper forms the ideal basis for a chapter in a thesis because you already have all the data. In the link cited below it is said by a PhD candidate that" I had published several papers, so I reorganized them into one coherent and logical story—writing a general background introduction, a chapter introducing my research topic more specifically, a description of the common instrumentation and data analysis, several adapted chapters presenting the original work of my research, and a general conclusion."
Dear Subhash Kumar I don't know if there are any official rules in that particular case. After all, it's both your own work and you can be lucky that parts of your planned thesis have already been published. Personally I would suggest to do some minor rephrasing in order to avoid any issues with self-plagiarism. With that in mind you can incorporate the entire publication in your planned thesis.
Other that obviously extending the length Subhash Kumar I guess you'd have to match that research paper to the contents of that particular chapter of your thesis. A research paper should have all the same headers but with very concise and precise contents due to the classic format of research / journal papers.
You will need to elaborate each part of your research paper with extensive literature review. You need to maximise the length of each section but make sure, you do not exaggerate. Overall, a thesis paper is a more detailed basement of a research paper. Rephrasing/ paraphrasing is necessary as well. You can add relevant frameworks to present your variables and graphs/charts to present your analysis in detailed way. Operational definitions and glossary should also be included.
In this article it is stated that "It is perfectly acceptable to use one of your previously published papers as your thesis chapter. In fact, there is a certain type of thesis that is created by compiling several of the author's published journal articles, adding just an introduction and conclusion. This is known as a cumulative thesis."
If your thesis has parts like introduction, literature review, methodology, results, discussions and references.
From your paper you pick background information and objectives and put them on introduction. Put literature reviewed on literature section. Put your materials and methods on methodology. Same is done for results, discussions and references.
Dear Subhash Kumar normally in a published research paper the results are reported in a shorter and more concise way than in a PhD thesis. In the thesis you can describe more details and even mention negative results. In any case a published paper forms the ideal basis for a chapter in a thesis because you already have all the data. In the link cited below it is said by a PhD candidate that" I had published several papers, so I reorganized them into one coherent and logical story—writing a general background introduction, a chapter introducing my research topic more specifically, a description of the common instrumentation and data analysis, several adapted chapters presenting the original work of my research, and a general conclusion."
Research paper is summary of your thesis , normally people write their thesis when accepted they try to extract paper from thesis , in your case you have to write in detail