There are many platforms where you can get smart study materials including YouTube. You can follow channels like Study Point, Competition's World etc.

Some of the best books that you can follow for preparation of BA LLB-

English Comprehension: High School English Grammar and Composition by Wren & Martin, Word Power made Easy by Norman Lewis

General knowledge and Current Affairs: Current Affairs Yearly by Arihant Publications and Read newspapers daily.

Legal Aptitude: Legal Awareness and Legal Aptitude by AP Bhardwaj

Mental ability: Verbal and Non-Verbal Reasoning by RS Aggarwal, Analytical and Logical Reasoning by RS Aggarwal.

Read our article-

https://law.careers360.com/articles/how-prepare-for-jmi-ba-llb