It doesn't seem like being blocked intentionally, could be a configuration error too, maybe Reddit's or maybe Jio's
As can be seen above, depending on the which
DNS server I use, I get different IP addresses. The 192.168.1.1 is my JioFI device, and the IP address retuned from Jio DNS Servers for
www.reddit.com has some sort of routing issue when accessed from certain networks. Even my Spectra connection cannot reach that IP address, it goes through some crazy routing loops.
So it's quiet possible that DNS records returned when queried through Jio DNS Servers, are not reachable from certain networks. Those using
Google DNS or something else shouldn't have seen any issues.