Tager's backdash is vulnerable on the last frames (20-23). You have 4 frames to punish it. Now assuming he does 360A, its invul starts on the 3rd frame, so you now have a 6 frames window to punish him. The more active frames your move has, the easier it will be. However since his backdash lasts 23 frames it is technically possible to punish him with any move if you're prepared. 720 is 5 frames, 360B is 6 (both without invul), so it should be slightly easier. However, you (most definitely) don't want to miss and being close to Tager on wakeup is definitely a risk... Especially when Valk can lame him out so easily and just run the entire game.
tl;dr if you can predict it you can punish it with excellent timing, or simply just gtfo and return to neutral where you own him anyway.