Hello Aspirant,

See if you think that you have not got all the concepts of class 1th an you want to re-appear for class 11th so yes you can and it will not affect any of your upcoming entrance exams because it is valid and legal so there will be no harm instead you will get knowledge of all those concept which are the weak point for you. If we talk about coaching then there is no need of coaching because much efficient study you can do at your home on your own which you cannot do in any coaching however there different pros and cons for coaching which we are not going to discuss.

Now as you are studying from Biology background so if you want to appear for NEET exam after passing class 12th then also you are eligible for it because there is no upper age limit to appear in NEET exam but there is lower age limit which is 17 years.

I hope this information helps you.

Good Luck!!