I am 2nd yr student of B.E(cs) from top college of M.P. Should i prepare for gates or for GRE ? please specify the reason for the same.

I am giving my exams of 2nd year and about to enter in 3rd year. I am average student with CG-PA of 7.0 . I have interest even in management, i get totally confused between Gates, GRE and cat. should i prefer to do job before my PG or i should complete my studies first? thank you