How get razor in dota?

You get Razor by going to the team scourge and click on each house's bottom left corner. Then you look on the left and you should be able to get it

If you meant to ask : How do I counter Razor in Dota, please repost.

If you're in the Sentinal, press enter(to type) and type in -ap. Then you can go to the Scourage's huts and choose Razor(the lefmost hut). You have to do this at the very beginnig before you do anything.