Here's a breakdown of the sentence:
* nattil - in the country
* evada - whose, of whom
* veedu - house
* veetil - in the house
* arkkey - key
* ondu - one
* enna - what
* ishtamano - is it liked?
This sentence is a bit of a strange phrase, as it's not something you'd typically say. It could be a rhetorical question or a way to express that having a key in your house is common.