Hi

If you dont want to do M. Tech you have following options

1. PSU 

Public sector is the dream job for any mechanical engineer. And you have got a very good rank you have good chance of getting into top PSUs.

Like NTPC, HPCL, BEML, BEL etc

2. JRF ( Junior Research Fellow )

Many IITs and IISc hire GATE qualified candidates as Project Assistant to work on sponsored project. You will be paid 30K per month.