i want to set marathi as language

http://www.apple.com/iphone-5c/specs/

Language support

English (U.S.), English (UK), Chinese (Simplified), Chinese (Traditional), French, German, Italian, Japanese, Korean, Spanish, Arabic, Catalan, Croatian, Czech, Danish, Dutch, Finnish, Greek, Hebrew, Hungarian, Indonesian, Malay, Norwegian, Polish, Portuguese, Portuguese (Brazil), Romanian, Russian, Slovak, Swedish, Thai, Turkish, Ukrainian, Vietnamese

Marathi does not appear to be a supported language in iOS 7.

Submit your feedback directly to Apple using the appropriate link on the Feedback page:

http://www.apple.com/feedback

You can read email and webpages in marathi, but there us no user interface yet

http://mr.wikipedia.org/wiki/मुखपृष्ठ

For a keyboard you can try the one for Hindi or the app called "Type Marathi".