i am ECE 2010 grad,working in TCS since dec.I want to give gate 2012.So shud i get experience certi from tcs before leaving it to avoid gap?

i want to give gate 2012. for good preparation i will have to leave TCS and then study for gate. But the thing is should i get an experience certificate for these months in TCS? would there be any problem in future placements if i dont have the experience certificate and this gap is counted as null?