i am having a comedk rank of 27000 and according to last year cutoffs i am getting nmit ece and rnsit cse. Pease tell me what should i prefer i a only concerned about placements

First of all, congratulations on getting selected for RNSIT and NMIT. You are lucky to have more than one option to choose from. Coming to the question, since you are only concerned about placements, a comparative analysis of the figures will help you decide better. 

From the above table, it can be inferred that RNST has a better placement scenario and the fact that you are getting CSE, one of the most coveted branches of Engineering in itself is a big achievement. 

Here is an additional list of companies that visited RNSIT last year and the highest packages they offered.

I asked a friend in RNSIT about the placement review and he told me that companies started visiting from the 6th semester and more than 1000 were made. The highest package offered was INR 56 LPA and the average package is around INR 6 LPA. Another friend at NMIT ECE told me that around 150 companies came for campus placements and the highest package recorded was INR 50 LPA while the average package recorded was INR 4 LPA.

In simple words, if you are after placements go for RNSIT CSE without any second thoughts.