I taken tc of 12th but i want to write the exam of 12 th

Subhadra, you haven't mentioned whether you have completed your 12th or you discontinued your 12th and collected your TC. This is important because if you have discontinued your 12th but want to appear for your 12th exams again, you ca take admission in NIOS. You can appear as a Private student as well. But if you have already passed your 12th and then want to rewrite your 12th exams again, then you have to appear for your improvement exams. Please do let us know which is the case and we shall help you with relevant information.

Hello,

you have taken TC which indicated that you have passed 12th. You want to improve your scores. check out if your 12th board is allowing for improvement exam. If it is then do prepare for the process and give your best.

if you studied under CBSE then you can appear Improvement exam. State government board may or may have the provision for improvement exam. it is only one chance. if and  only if any student fail then they are eligible for compartment exam.

Hope it helps!