Is it possible to do Ph. D. after B. Tech. without doing post graduation (M. Tech./M.S.), if having some years R&D experience. Please inform part time and distant learning options also.
Yes there are opportunities for you to do PhD. with out doing M.Tech. It is called as direct PhD offer. Only criterion is you should have good CGPA in B.Tech. and one more chance is that you should be from top institute and further your research experience will also help you in getting direct PhD offer. In IIT Hyderabad it is possible to do PhD both regular and part time.
It is possible but one need to have certain years of research experience and a few good papers, as per the rules of the institute. I think in India, you may get in touch with IIT (BHU, Varanasi) and IIT-Bombay (Mumbai) and find out whether it is possible (these days).
While taking admission in foreign universities, it must be noted that the foreign university must be recognized by AIU (Association of Indian universities) else the degree will be not valid in India (especially for government sector jobs)
As per me (I am not sure) only less than 20 universities around the world is recognized by AIU
It is possible, but highly unlikely. I suggest you rather register for a masters by research only and if it turns out that you are making a significant contribution to knowledge, then convert to a PhD.