Hello Prithviraj !

It's not compulsory to go for coaching. If you are confident, you can definitely prepare yourself.

It is advisable to start preparing for neet from 11th itself as class 11 syllabus is the base for the entire syallubus.

By working hard and putting enough time you can crack neet exam.

Here are some preparation tips for neet exam :-

1. Collect all the study material (preferably ncert) and go through it.

2. Practice last year papes to get an idea about the exam pattern. There are chances for similar questions to be asked.

3. Make a time table and divide the chapters according to it and complete it on time.

4. Practice basics until your fundamentals are clear.

5. Focus on the chapters that carry more marks and keep revising them.

6. Prepare a list of the important formulae and stick it in front of you so that you can revise whenever possible.

7. Go through mock tests so that you know where you stand.

8. Time management is very important for neet. So ensure that you are solving the model papers within the time limit.

With your skills and efforts, you can definitely clear the new exam. Also, remember that along with preparations, proper diet and suffient test is also important.

All the best !

It is totally up to you. You can prepare well by your own if possible. But in that case periodic assessment ( online & offline tests) is necessary to evaluate how's your preparation is progressing.