Transfer money from overseas subsidiary

I have couple of Questions. 

1. Are there any rules for india regitered private limited company to open its subsidiary overseas to be followed in India? 

2. This foreign resitered company will invoice the overseas customer. What is the best way to transfer money from this foreign registered company to India? How about taxation? 

3. Can an indian registered company raise invoice directly to overseas customers? From a tax perspective which works well. Is it to invoice a overseas customer for the services offered from an Indian company or from a foreign company and later transfer the amount from the overseas entity?

Thanks

Sankar Rao