Before this you can also see what is the difference between V1, V2 & Hybrid here
Now you can identify the version of Torrent file in 
TORRENT PRO app by going to details page of the particular app
And by technically you can also identify versioning of the torrent by checking it’s magnet link, Magnet link prefix will be tell you the version of Torrent
Version 1 (V1) Torrents: the prefix of the Torrent for v1 SHA-1 info-hashes is urn:btih:
The example of V1 Torrent is like magnet:?xt=urn:btmh:<tagged-info-hash>&dn=<name>&tr=<tracker-url>
Version 2 (V2) Torrents: the prefix of the Torrent for v2 SHA-256 info-hashes is urn:btmh
The example of V2 Torrent is like magnet:?xt=urn:btmh:<tagged-info-hash>&dn=<name>&tr=<tracker-url>
Hybrid Torrents: A hybrid torrent has two info-hashes, one v1 SHA-1 hash one (possibly truncated) SHA-256 hash. This forms two swarms, or a segregated swarm. libtorrent marks peers as supporting v2 or not. This information is also relayed via a new peer exchange (PEX) flag. It includes both urn:btih: & urn:btmh
A hybrid .torrent file includes both piece hashes as well as the tree root hashes for each file.
The example of Hybrid(Backward Compatible) Torrent is like
magnet:?xt=urn:btih:631a31dd0a46257d5078c0dee4e66e26f73e42ac&xt=urn:btmh:1220d8dd32ac93357c368556af3ac1d95c9d76bd0dff6fa9833ecdac3d53134efabb&dn=bittorrent-v1-v2-hybrid-test
Like this you can identify the version of the Torrent.