Hi Vikas, 

I am very sorry to say that as per Information bulletin of NEET UG 2018 and amendment in Graduate Medical Education Regulations, Candidates who have passed 10+2 from NIOS or state open school or as a private candidate are not eligible to appear for NEET UG. Furthermore, study of Biology/Biotechnology as an additional subject at 10+2 level shall not be permissible. 

Hope this helped. all the best for your future. :) 

You will have to choose code 2 as you come under this category only if you have completed your 12th in earlier years.

Good Luck!!!