Hello upadhya rajukanth,

The gate is entrance exam for the pursing of the masters in your specific stream .

If you qualified and secured better rank in the gate examination then you can pursue your masters in the gate offered college .

Or else you can write the pgecet of your state for the masters in your state colleges.

Gate is not mandatory for the pgecet. But the application date is finished you don't have chances now. 

All the best