Whether I should go for both group or single group of IPCC??

I am very much in two minds....I have cleared my CPT with 144 marks...I just wanna ask whether should i go for both groups or single group....What are the benefits of giving both groups????I passed my 12th with 79.4% in 12th(I was not that serious in studies at that time than I am right now) and What are the benefits of getting a Rank in IPCC???Reply me ASAP