Hi debrupishere - sorry about the score but it's common for people to have a worse showing in the actual exam than they do on practice tests (even the difference that you saw of 720 -> 650 is not at all unusual). Frequently people test better the second time just because they know what to expect and handle the pacing issues better - so it's great to hear that you're planning to retest. You would probably need to try again earlier than later though if you want to apply for this admissions season. It sounds like you're young enough, with just two years of work experience, that it also could benefit you significantly to wait till next year to apply - obviously it all depends on your personal situation etc., but having a better GMAT score, and applying in Rd 1, are both strongly advisable strategies for Indian candidates.
Regardless you asked about which schools you can target with a 650, and there's a lot of really fine programs out there who have average student scores at that level. You should search around to identify programs that are suited to helping you with the career goals you've defined - that's really the most important factor in choosing schools. First you should figure out which schools can help you meet your goals, then you can deterimine if you're a good fit to them. There's other aspects like geography, size of school, etc. etc. etc. that also come into play - these are very personal decisions and in fact every school is quite different (even though they all start to sound alike when you're reviewing their websites!!). So you get to have some fun in doing the research and understanding what the schools are about, then deciding for yourself where would be a good fit.
Note that even the lower-ranked schools (e.g., Tippie, Babcock, Fisher, Smith - just throwing out names here) are still quite competitive, particularly among those from oversubscribed pools like Indian males in engineering. So, getting to work now on an application to be submitted for next season isn't too early! Of course, if you're planning on applying THIS season, then you need to get hustling.
A higher GMAT score could open more doors to you, but there's still plenty of strong MBA opportunities out there with a 650 GMAT too. Selecting the right one will depend on what you want to do with the MBA and your own personal priorities.
Best of luck!!
EssaySnark