I would strongly recommend jamboree institute Raja garden for GRE, Gmat, SAT and all related exams. I, myself, am a student here, taking classes for GRE and the faculty here is very supportive and clears all your doubts.
You get all the attention you require to get a great score in GRE. The competition you get, here at jamboree prepares you for the exam. The environment is very nice for learning. Jamboree gives the mock tests for gre and all such exams which are really very helpful and after the completion of the classes the students are full of confidence and can give the exams without any hesitation and nervousness.
So, Jamboree is a great institute which really helps you land into a good college.