There is no any common entrance exam for LLB programme. LLB programme admission is based on university level. The top universities for LLB programme University of Delhi- There is no any age limit to apply for the programme. You can check the complete eligibility with given below link.

DULLB Eligibility

Banaras Hindu University- There is age limit as you should not be more than 30 years as a general category & not more than 35 as a reserved category. You can check the further eligibility with given below link.

BHU LLB Eligibility

In case you wish to take admission in any particular college then let me know.

Good Luck!