Yes, IIEST takes the admission through JEE Main.The candidate should have minimum 75% (for GEN or OBC-NCL) oraminimum 65 %(for SC, ST or PwD) of aggregate marks in the Class XII (or equivalent) examination ofrespective stream and Board. For further detail about the eligibility you can go through with given below link.

IIEST Admission

Therefore, you are not eligible.

In order to take admission in IIEST you should have obtained at least 75% marks in aggregate in Class XII (or equivalent) board examination.For SC, ST and PD candidates, the eligibility criteria in class 12th is at least 65% in aggregate.