Yes,

Few colleges allow students to pursue M.Tech-PHd dual degree to the B.Tech graduates.

Link of two colleges are given below-

IIT Jodhpur (http://iitj.ac.in/academics/index.php?id=acad_program&&prog=50)

IIT Kharagpur (http://www.iitkgp.ac.in/files/phd_ad.pdf)

You can search for more colleges and also contact them to know about the eligibility conditions as the admission process will vary from one college to another.

Dear Rekha

Yes, you can. IF you can able to qualify the Gate exam after B.Tech then definitely you're eligible to do Ph.d. It needs lot of knowledge and also you need to publish some papers too. So please take care of that.

All the best.

Hi, Ye you can apply for PhD after Btech. You shall get a chance to study with highly competitive students. Usually it takes 4-5 years to apply for PhD. You will have to make a list of universities that admit students for PhD and at the same time make a list of professors whose work interests you and do not forget to look up at their publications. Try to reach them through mail or call preferably. All this process shall start at least 5-8 months before you plan to start the PHD. Hope this makes sense for you. Good Luck.