Dear Abhishek, please go to the link https://www.nta.ac.in. Register yourself with the details requested. Later login with your credentials and select NEET 2019 as the mock test exam and select the paper of your choice. It is a pen paper based test. Hope this helps. 

hii abhishek

Yes,NTA is providing mock test,to register for mock test,you need to go to the official website of NTA and register there and then you will be provided a exam center for giving mock test.i hope this information helps you.

thank you