Where are Galatine stance mods please ?

[Goritude]

I have no Galatine (sword ?) stance mod. Where can I farm efficiently ?

[RNG_Wizard]

The Galatine is considered a heavy blade, so it uses three different stances

Rending Crane, which isn't popular or very powerful can be farmed from Grineer Napalms.

Tempo Royale, a highly mobile and fun stance, drops from Rathuum and Bursas. It's very rare, so it's probably better to wait for Baro Ki'teer to bring Tempo Royale if you want it.

Cleaving Whirlwind is probably the best of the heavy blade stances, and can be farmed from Infested Dsiruptors and Tar MOAs. Basically, run any infested survival or defense, and you'll hopefully get it eventually, although it is a somewhat rare drop. It also drops from spy missions on LUA, if you don't want to fight infested enemies.

Also, the Warframe wiki is your friend.