Oh wow. What a thought!!!
http://www.hindustantimes.com/static/fgm-indias-dark-secret/
Not sure why, but I never thought this was a practice there.
While any scenario is possible, the genital mutilation practice of an Islamic sect (Bohras as described in the article) is hardly representative of the rest of India. The article linked is about the problem within this specific community.
So Syrian Christians with roots in Kerala practicing female genital mutilation highly improbable.