CBSE

If you have scored 75% in 12 board and determined to get into IITs or NITs you should take drop and achieve what you want.

You can give either 2nd, 3rd or even 4th time. But the thing is that while giving improvement exam you should not be enrolled for any UG course.

Original marks (70 and 65) will be considered for college admission.

As per CBSE Revised Rules of correction/change in name/ DoB are as under :
Application for correction in name of Candidate/Fathers/Mothers/ Guardians name will be considered only within one year of the date of declaration of result provided the application of the candidate is forwarded by the Head of Institution with the following attested documents:
So in your case there is a gap of more than 7 years after declaration of result. So correction in CBSE marksheet is very difficult. Please ask to concerned school or CBSE regarding this.

You can pursue a Bachelor of Science in Hospitality and Hotel administration or B.Sc. In food Science or microbiology Degree but for a core Biology subject, you were needed to opt for Biology in class 12th only then you can do B.Sc. Specialisation In Zoology or botany etc. Even I opted Biology and Biotechnology in 12th that is how I was able to do both.

The Central Board of Secondary Education (CBSE) is a national-level board of education in India for public and private schools, controlled and managed by the Government of India. A list of the CBSE schools in Hyderabad is given below
1- Santino's Global School
2- T. I. M.E School
3- Elate International School.
4- Lakshya International School
5- Arka International School
6- Rockwell International School
7- St. Peter's High School, etc.

Yes, you should register for private institution, then you can appear for the exam privately.

You are eligible for BBA and B.Com (Hons) for good college in Ahmedabad and please apply soon to college near you, You are late for now because once you get you results, the immediate action to be taken is apply for as many college as possible irrespective of your marks. College work on first come first serve basis.

You can appear in maximum 4 subjects under NIOS scheme to do medical group in NIOS board under part admission eg Chemistry Physics and Biology go ahead last date is 15th September 2022 with late fee 700.