What about "Koi baat nahi, anytime"? meaning "No problem, anytime" (Although this sounds informal) Or you can also use the english "you're welcome"... I think most of the people in India would use this instead of the actual Hindi form....

you are welcome--aapka swagat hai aapka-you, swagat-welcome

you are welcome - aapka swagat hain but usually in Hindi culture we never reply like "aap ka swagat hain (you are welcome) " when some one say " sukriya (thanks)" . you can just smile if you are infront of person.