Dear Animesh,

Total no. of seats Through IIT is just 6875. AS your rank is quite closer to it you cant expect anything good here. Since the new IITs has starte with the core courses onlt ( mech., comp., elec., civil ) most of the students above you prefering these colleges and you will be left with some very branch at ISM dhanbad.

Regarding AIEEE your rank is quite good and you could hope for the best. At this rank of yours you would be either getting Civil or Chemical at NIT Trichy or other good branches at other best NITs. You should prefer Comp. Sc. or electriacal at other NITs

for last year cutoff details of different college refer : -

www.askiitians.com/aieee-counselling/aieee-engineering-counsellings.aspx

I think its better for you to opt for NITs rather than going for RV college.

For ranking of RV college refer : -

cetinformation.com/ranking.html

Regarding your query about the best colleges than obviously IITs are better tahn other colleges except that some of the NITs are better than ROORkee and guwhati.

Refer to the link below to get the ranking  : -

www.successcds.net/engineeringentranceexam/Top-100-Engineering-Colleges.php

Thank you.