Dear Yogyata
You may use the letter head with the registered office address of USA.
As the company has not started their operations in India ,nor do they have a office in India, it would be better that you do not employee people as employees but as Consultants. A letter stating their consultant status with the company and their compensation and benefit also their roles and responsibilities to the respective people
The company may also enter into a MoU with the so called consultants, assuring them that they will be absorbed by the company as soon as the company fulfills the required statutory provisions (only if the need arise, need the MoU needs to be worked out between your Bosses company and the employee).
As matter of precaution the jurisdiction in case of any issue arise can be kept as both India and USA, with primary cause for any legal case of action arising at India.
By doing the following procedure, the company can evade temporarily Company law complication also to a certain extend it would be easy for your Boss to wind up business if the same doesn't do well, as all the employee employed with company would be consultants
This procedure is applicable only for Top and middle level management cadre people and not for staff, and if something similar has to be worked out for staff, then a different approach has to be adopted.
Hope this solves your query
Thank You
Octavious