Hello Anubhav.
Last date to apply for SRMJEE is 20th april and if you apply today it is completly fine.I am attesting the link for your reference
https://applications.srmuniv.ac.in/btech?utm_source=careers360&utm_medium=001if&utm_campaign=srmuniv

***Steps for booking a slot and downloading hall ticket is as follows:-

(1)First step is to enter email ID and password
(2)Next, you need to select the slot, date and time
(3)Confirm your preferred exam centre
(4)Enter submit, and you can download a copy of hall ticket

The admit Card will be available in official site.Slot booking should be done before downloading the admit card.The printout of the admit card should be carried along to the examination hall. Original copy of your Aadhar Card should also be carried  to the examination hall.

***Following are the steps to be followed for downloading admit card:

(1)After the slot booking, the option of downloading the admit card is displayed on the screen.
(2)You can download your admit card and take a printout of the same. Please ensure that the details printed on the admit card is ok.

I am providing you another link which will be very beficial to you.

https://engineering.careers360.com/articles/srmjeee-sample-papers

Link consists of some sample test papers and some detialed information regarding the college campus and examination.

Hope you find this information useful

All the best for your future endeavor.