There is no age bar to apply for Law entrance exams. After completing your Graduation you can apply for three year law programme. There are many universities offer three years law programme, Some of the universities name given below you can prefer for three years law programme.

Faculty of Law Delhi University

Faculty of Law Banaras Hindu University

Punjab University etc. You can check the eligibility to apply for the universities with the given below links.

https://law.careers360.com/articles/du-llb-eligibility-criteria

https://law.careers360.com/articles/bhu-llb-eligibility-criteria

https://law.careers360.com/articles/pu-llb-eligibility-criteria

If you are interested to take admission in any particular college then let me know.

Good Luck!