Research is not necessarily required but if you do not have it, you should be able to make up for the lack with other extracurriculars. Of course you should be able to talk about your research/volunteering/organizations. Another thing is research is interesting in that it presents the candidate in a different way, especially in terms of how they think. Which is something you should consider.
Of course students are evaluated on their characteristic traits, ethics being the most important. Though you should note that students with a high rank (top 10) but a less than 65 CBSE will end up with 2-3 interviews. Students with a high CBSE (75+) but not as high rank will typically have 10+ interviews.
One thing that was particularly surprising to me was that if you are planning on applying to a 6 year program, if you have an undergraduate GPA of less than 3.3 or 3.2, you will have a very hard time getting in. They seem to have a cut off undergrad GPA when looking for candidates. So, undergrad GPA matters! Who knew! ***