Hi,
If you talk about MBA, a GMAT might not mean instant gratification. A GMAT score lasts for 5 years and and most schools need work ex (even ISB in India or any other school that accepts GMAT). So if you want to do an MBA you can give your GMAT now as you are still studying and concepts are fresh in your mind. The other way is to give the CAT and do an MBA. Again it is for you to decide if you want to pursue an MBA in India or abroad.
So I would suggest give the GMAT and get a job and then see where life takes you. You can use the score in the next 5 years so thr is no harm. Anyways GMAT changes next June so it makes complete sense to give it even if you decide not to pursue a course right now.
I hope it helps.
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