Hello Sanskar.

As per your concern, NTA is conducting mock tests held at TPC for students who have no access to the internet. But you can simply go through the online mock test series provided by NTA.  Here is the portal to avail the mock test.

https://www.nta.ac.in/Quiz

As soon as you open the link, the portal having all sort of tests conducted by NTA can be chosen. You can go through JEE main and choose a certain paper to start with. You don't have to create any id, just click on the login button and start the test for 3 hours.

All the best for the exam!