Hello Sharmila j 

As far as excellence of a coaching centre is concerned I think it is a very subjective approach . Although this institution has provided good results in past still I would say that the approach of a candidate towards that exam matters the most.

Almost all the good institution follow same statergy of taking test , doing previous years papers and revision.As a repeater if you have already done any coaching in past I will suggest you to not join any institutes but rather revise whatever you have done already by staying at home.It will save your time and give you an edge over others.Also solve as many question papers as you can and in case you have any doubts refer to online sources for clearing them.

All the best