Hello Sam

see if you have failed class 11 th there is no need to worry.

You have ample things you can do ow firstly as you said you can apply for class 12th from CBSE open school but for that you need to have cleared 11 th class 1st.

Now you should have a minimum of 50% in PHYSICS ,CHEMISTRY,BIOLOGY of class 12th for NEET

So you should first focus on clearing class 11 th with nice merit.

Best of luck for future.

Thankyou.