Are there any risks to using Tor browser? Does it make you more prone to being hacked, since a majority of hacker community is using Tor?
It is almost secure and it doesn't matter hackers are also using TOR for anonymity. Since the traffic is encrypted at every hop your communication will be secure till the exit node of TOR.
It is the node where your Traffic leaves the anonymous network and enters into the open Internet. From there your traffic can be monitored. If anyone wants to sniff the traffic then they can sniff at the exit node. If you are browsing service which is not using HTTPS then there will be a problem since the traffic is not encrypted after exiting the exit node of the TOR network.
This is the image I've taken from the Internet to explain.
You can see there is exit node/relay from there your traffic goes out of TOR. There onwards the traffic can be sniffed. If you are browsing Facebook then there is no harm because the traffic is encrypted. So when it will leave the TOR network then it will be encrypted as well.