ohh wayanad aruno. Okay.
Depends. The Syrian Catholics ("SyroMalabar") of Malabar were most probably from Palai/Kottayam side.
While Orthodox and MarThomas were definitely from modern Pathanthamthitta district (I say modern as Pathanmthitta district was only formed in the 80s from Kollam district).
most migrations happened in 40s/50s and 60s time.