Hey Jaskaran.

There are various different entrance examination for admission to law courses in India.

Most of these entrances have a syllabus which includes General Knowledge, Verbal Ability and Language, Legal reasoning, Quantitative Aptitude, Logical reasoning etc.

You can use an all inclusive guide like Universal's guide to LLB and CLAT which includes basics and practice questions for all these topics. Other than that you can refer to previous year question papers for each entrance for a better guidance. For current affairs and verbal section the Hindu is considered as the best newspaper. You can use Word power made easy- Norman lewis for vocabulary. You can use R.S aggarwal'a books for Logical Reasoning or quantitative section in case you need a separate book other than universal's guide.

Make sure you practice a lot using previous years question papers for a better rank.
But this will also depend on the entrance test. Some entrances for 5 year law like CLAT, AILET or 3 year law like DU LLB are very competitive and level of difficulty is higher you might need other sources too.
Best of luck!