Hello Atish,


I hope you are doing well.


Your scenario is that you have not done studied AISSCE, so in that case you wont be able to persue graduation but no issue as you can persue graduation in BA, but dear this is a horrible option because you have perured technical study for 3 years and bow you are switching to a subject that has no connection with what you have been studying for 3 years.
So, my advise for you would be to do btech and mtech or else btch and after that you can prepare for GATE and thay would be good for you.
Further its up to you and your choice.


Best of luck !