In Kerala most of mosque prayers are in Malayalam. I don’t know whether they do same in tamilnadu
That’s in utterly bad taste. Not sure what offended you. But there is no need to call in Muslims and mosques in this conversation.
Was your argument not about replacing non-local languages like Sanskrit and Arabic (used exclusively for liturgical purposes in Tamil Nadu) with local languages like Tamil? If not, it might be useful if you spelled your argument out.