evidently, it can be grown, I'd suggest contacting a university or a local farmer there. Possibly there is avariety that is adapted to the climate and day length, which might be significant.

Here is a link that might be useful: PRODUCTION OF ALLIUMS IN SRI LANKA

There is warm weather gralic already adapted to the culture. I am growing a phillippine garlic named Palawa that is performing well for me. If I remember from when I lived there, they had several varieties and I think one was a hardneck.

Warthog