Yes, IIST takes admission through JEE Advanced.

In order to be eligible for JEE Advanced you have to qualify for JEE Main exam first.

In order to be eligible for IIST exam you should have aggregate 75% marks in your boards exams. For SC/ST and PD it is 65% marks. 

For aggregate you have to consider P/C/M, Language and one any other subject. 

Good Luck!!