1- Request the company to cancel the visa and apply for a new visa.

2- Let him come come to Qatar on the current visa he is holding, and after he come he can apply for resident permit under the new company name, but for this you have to get NOC from the current sponsor/company who issued the visa. If you are not sure of getting NOC don't try for this option.

3- Wait till the current visa expires and apply for a new one