how to transfer videos from pc to iphone?

Hey Man! Khan,

Welcome to Apple Support Communities.

It sounds like you want to know how to sync videos from your PC to your iPhone 6 using iTunes. If you haven’t already, add the videos to iTunes as shown here:

Ways to add items to iTunes - iTunes Help

Then sync the videos to your iPhone 6 as shown in the article below.

Sync your iPhone, iPad, and iPod with iTunes using USB - Apple Support

If you can’t sync the videos because of the format they are in, try converting them as shown in this article:

iTunes: Videos may be unable to sync to iPhone, iPad, or iPod - Apple Support

Cheers,

-Jason