Hello student I'm sorry to inform you but not you can't pursue Mathematics subject at Senior Secondary level (+2) if you've opted for basic Maths in class 10.

You can pursue subjects like Physics Chemistry Biology, (PCB, Science) Commerce or Humanities in class 12.

The CBSE also give an option to students to appear in Standard level Mathematics in compartment examination if they've changed their mind. They must qualify in the basic Mathematics examination.

For more details refer to the link mentioned below - https://news.careers360.com/cbse-maths-no-longer-threat-in-class-10/amp

Feel free to comment if you've any doubt

Good luck