I don't there will be a big issue in terms of clash because Atrangi Re isn't an Akki starrer, it's a movie "with" Akshay Kumar. Very likely it's an extended cameo and it makes better sense for AR movie to release on Valentines than Kaithi.
If the makers were really looking for a good weekend for an action movie, Republic Day is just 3 weeks before V-Day. However, that one has a full fledged Akki movie releasing, that's why they picked this other date.
There's a good opportunity to use RRR to promote this movie as well. Maybe another solo Blockbuster for Ajay on the cards.
Looking forward to this movie. Personally I hope it clashes with Atrangi Re and crushes that movie. I want ALR to suffer.