Total 3 rounds are there:
Written Coding Test
Technical Interview
HR Interview
Level of coding questions are quite average overall. If suppose there are 6 questions then the cut off will be at lest 4 right answers. B.tech percentage also plays a vital role in selection process, if your percentage is above 80% then your chances of clearing is high.
Technical Interview is quite though, they will ask you anything from your resume and work that you have done, like internships and projects. So always write your true skills.
HR round is the most fun round, be frank and have a positive attitude. Be confident but not over confident.
All and all they look if you are trainable or not and try to have some decent communication skills, that's all.