Hello.
Since you can considered that there  is great aptitude portion in CAT examination so if you can solve question of this examination that means you would be having good knowledge or command over it so  I would suggest you to go through the official website of IIM where you can solve mock test paper of CAT exam free and try to attempt aptitude portion with full focus that is going to be beneficial for you, so you can take the help of below link in order to know the full process to view the mock test:
https://bschool.careers360.com/articles/cat-mock-test
Best of luck.