I dont know bro but when i tried to fill it up... in the qualifying degree option there were options given on b.sc. as there was a simple b.sc. and b.sc(Research)/b.s. so there might be a chance and i too myself havent confirmed that with the authorities but i still filled it up... only they can tell us for sure about that. i can even share the image of screenshot that i took where it shows different types and if you check eligibilty on the portal it says anyone in their 3rd year or higher pursuing or completed their undergraduate course in any government approved degree program in engineering/technology/architecture/science/commerce/arts. so i would suggest that you at least try since today is the last day... there is no fault in trying but there is a lot in not trying and afterwards you can ask the authority like i will do confirm my queries so that i can peacefully study for it without the tension that my application will get cancelled due to eligibilty criteria.
You are not eligible for this exam if you are pursuing BSc(3 year degree) with the exception BSc in Research /BS are eligible.There is a revised creteria for GATE 2021 if you are pusruing BSc in research(4 year degree) and currently in 3rd year or in higher grade or completed then you are eligible.You can check here the details of eligibility