There are free courses available on Artificial Intelligence which are offered by IIT's at NPTEL. Doing the courses here are for free but if you wish to get a online certificate, then you have to pay Rs. 1000 as an examination fee & on qualifying the examination you will be provided a online certificate of the course you have completed & this certificate will be verifiable by the IIT's.

If you are wanting such courses then do download the Swayam NPTEL app or visit the swayam website by visiting the link provided below:

https://swayam.gov.in/

I hope this helps. Wish you a great day!