Yes, I think this is the case, too. Also, there are many Indians in the Church of the East--how many, I'm not sure. Nor am I sure about their geographical spread. I didn't think there were any at first, but later found out that there were.
Mainly Kerala, too. Wikipedia says that (paradoxically) the metropolis Assyria is the biggest diocese in the Assyrian Church (that's very probable, because of all these divisions and persecutions in Iraq and Iran - only in India there is intercomunion and an agreement to have one metropolitan between 2 Assyrian fractions).
I know that Assyrians are more heretical than Roman Catholic, but, to tell the truth, I rally like them (maybe because of this perceptible semitism).
What I know, only during last years (20?) the Malankara Orthodox has making some missionary effort in India e.g translating the Liturgy in Hindi.
So, that's nice that Eastern Orthodoxy is growing in other parts of India and what I can observe (e.g from theortohodoxchurch.info), Malankara really appreciate this EO presence in India (it seems that Malanakara is more open for EO and consider us in some way as one Church). And it was unfortunate what Portuguese did in Kerala and surrounding provinces. Fortunately, most of Malankars haven't chosen the way of union or giving up its own practices for latin ones.
PS: I used to study indology for some time that's why I have some information about the Christianity in India. And really, it's quite large (e.g in the eastern north there are some provinces with 90% of Christians, unfortunately mainly anglicans and protestants), and many e.g Hindus even from other parts than Kerala, Karnataka etc. know taht about the Malankara Orthodox (of course, they don't differentiate it with EO, for them it's one Orthodox Church).