Getting a B.Tech degree certificate from Kerala University, might take around 3 months. But if it is urgent, you could submit the application form along with a request stating your urgency.
Firstly you need to apply for a provisional certificate. Once you get that, you can apply for the original degree certificate along with the copies of the provisional certificate, mark sheets, and challan (original) to the concerned section or COE.
After verification, you will get the degree certificate within 3-6 months. It will be delivered via registered post.
This could sometimes vary as it depends on the person handling your college. If he wishes he could speed up the process.