Hello Aspirant,
No, i don't think you can change your subject now after studying basic maths the whole year. I don't think even it's allowed to change now according to CBSE, but still to be very sure talk in your school and see if there's a solution.
And if you want to study maths in +2 you can go for Applied Maths, you're eligible for it but not the main core Mathematics.
Hope this Helps!
All the best!
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