Hey there,

Well, clearly coaching is not as such mandatory but here's the catch, you really want to be thorough and familiar with the exam pattern and what you can expect in the exam question paper, you need someone to guide you throughout the process and analyse you at the same time 

And that's what coaching institutes can help you with. Still, if you feel that you are well-versed with the Exam paper pattern and all you need is resources to study from then certainly you can go ahead with your own preparation. I can lend down information regarding coaching institutions but since your main concern is whether you can do it on your own so I'll focus on that and will try to help you go forward with that if that's what you are willing to do.

You can seek help from various mock tests, sample papers & previous years' question papers available online as well as offline.  

For instance, by now you must be knowing the exam paper pattern which is divided into 5 categories namely-

• English (Comprehension & grammar-based)

• Legal Aptitude

• Logical Reasoning

• Elementary Mathematics (Including Numerical Ability)

• General Knowledge and Current Affairs

So if we proceed subject-wise, 

• For English, you can refer to the books-

• Word Power Made Easy by Norman Lewis
• High School English Grammar and Composition by Wren & Martin
• Previous years' question papers

• For Logical reasoning,
• Verbal and Non-Verbal Reasoning by RS Aggarwal
• Analytical and Logical Reasoning by R.S. Aggarwal

• For General Knowledge-
• Pearson General Knowledge Manual 2019
• Lucent’s General Knowledge
• Daily reading of newspaper
• Previous year's question papers

• For Legal Aptitude -
• Universal’s CLAT Guide

• For Elementary Mathematics-

• Quantitative Aptitude by RS Aggarwal

• Class 10th NCERT Textbook

And if you need more detailed look out, go on the link mentioned below-

https://www.google.com/amp/s/law.careers360.com/articles/best-books-for-clat-2019/amp

I'm hoping that the above-mentioned information resolves your query, in case you have any further question- feel free to comment below.

Wish you All the Best!