HOW to apply for NIOS biology alone I've passed out of class 12 but without biology When is the last date to do so?

I did read your previous question and so am writing this answer based on that. NEET is the entrance examination for admission to MBBS,BDS, Ayush and Veterinary courses across India. And to be eligible for NEET, you should have completed your 12th, passed in all subjects and secure a minimum aggregate of 50% in Physics, Chemistry and Biology/Biotechnology. It is 50% for General Category, 45% for PWD and 40% for OBC,SC,ST. Now if you belong to OBC Category, the Category you belong to should be also listed in the Central OBC list. Or else you will be considered as General Category and so you have to secure a minimum aggregate of 50% in Physics, Chemistry and Biology/Biotechnology. This 50% is inclusive of the Theory and Practical marks scored in Physics, Chemistry and Biology collectively. You needn't score 50% in Physics, 50% in Chemistry and 50% in Biology/Biotechnology separately. You need an aggregate of 50% or 40% depending on your Category as an aggregate in Physics, Chemistry and Biology/Biotechnology. And along with Physics, Chemistry and Biology/Biotechnology, you should also have studied English as one of the core subjects in your 12th.
Now you can study either Biology or Biotechnology to be eligible for NEET. And so if you managed to score the aggregate against your Category, you are eligible for NEET and because AIIMS and JIPMER take their admission through NEET score, should you score good in NEET, you can take admission not just in AIIMS or JIPMER but across Indiia. You needn't study Biology separately again.