Hello Nirmal,
You can prepare and appear for the following entrance exams for admission to three year LLB course-

University of Delhi (DU) LLB entrance exam

BHU UET Law exam for admission to Law school, Banaras Hindu University

Panjab University entrance exam

AP LAWCET- for admission to law colleges in AP affiliated to state Universities.

Good Luck!

CLAT is mostly acceptable for top colleges in India for LLB. AIBe, MHTCET Law, AILeT  are otger top exams accepted by decent colleges. List of all law college for LLB ciurses and accepted exams below. 

https://law.careers360.com/colleges/list-of-law-colleges-in-India?f%5B0%5D=sm_college_degree%3ALL.B.&sort_filter=parameter