The Indian government has blocked TMDB and different ISP’s are imposing the block differently than others. For some it seems as though it’s just a DNS block, which means you can change your nameservers to get around it. Others seem to do more than that.
If you want to try switching your nameservers, you can try:
- 8.8.8.8 (Google)
- 9.9.9.9 (Quad9)
See also The API is not giving response in all devices. - Talk — The Movie Database (TMDB)