Q: My iphone 6s is overheated when i m using it.Should i take it to the service center?

Howdy Ncyhahaha,

It sounds like you're concerned about the temperature of your iPhone 6s because it's getting warm when playing music. The article below should address your concerns as it provides a lot of great information about operating temperatures and the temperature management of iOS devices. 

Keeping iPhone, iPad, and iPod touch within acceptable operating temperatures - Apple Support

Cheers.