Dear Kan Rai,

SRM slot booking is already started from 9th April 2018.

There is as such no last date.

You can download your admit card till 30th April 2018.

SRMJEEE exam is from April 16 to 30, 2018

To book your slot you can refer below link

https://engineering.careers360.com/articles/srmjeee-slot-booking

Good Luck!!