Website in Indian regional languages

Hi

I need to create copies of my English website in multiple Indian regional languages like Hindi, MArathi, Kannada, etc. I am aware that this would need 2 things for starters:
1. The language pack
2. The Indic plugin to enable me to type my pages/post content in that regional language.

My question is : What do I need to do to ensure that the sidebar widgets, the navigation bar, etc also appear in the regional language. The main website is at english.mysite.com. If I need to create hindi.mysite.com – will it mean creating the whole site all over again over a fresh WP installation? Or, can I use the existing site in any way ?

Regards
Prayag