How to send employee to onsite

We are small IT (65 employee) website development firm based in india, but not listed as PVT Ltd it’s proprietor firm. company establishment in 2011.

We are doing business with US company since last 3 year, now they want to call our employee on site so he can work there with us from there end,

so how we need to process this visa? I am totally new on this subject.

You should hire an experienced attorney to guide you through this process.