You should join neet coaching after 10th.since the neet syllabus is based on 11 th and 12th.
If you join coaching after 12th , you will be dropping one year. I have droped 1 year for neet and I didn’t get selected and so I’m regretting it.
Instead I should have joined earlier after 10 th which would have helped me for my boards as well
Even If you don’t want to join coaching study your self with full dedication
If you want to clear neet prepare your self for it from 11th
Read ncert completely and revise it