Some firewalls can detect and block connections to Tor. The Tor Browser includes some circumvention tools for getting around blocking firewalls. These circumvention tools are called Pluggable Transports. To turn them on, click "Configure" in the Tor launcher window.
Select yes when asked if your internet service provider blocks connections to Tor."
Select "Connect with provided bridges". Tor Browser has three Pluggable Transports to choose from. If one fails to get you online, try selecting a different transport.
If you try all three transports, and none of them get you online, select "Enter custom bridges", and enter bridges manually. Read the Getting Bridges section for instructions on getting custom bridges.