Do I need a PAN card to avoid deduction from my salary if I have a Business Visa?

I came to India for an internship, and got a Business Visa.

In the company where I’m working they say they have to deduct from my salary(stipend) since I don’t have a PAN card.

I know some other interns (foreigners) in India, who are also on business visa, without a PAN card, and their company doesn’t need to deduct from their salary(stipend).

Please provide the details of the regulations regarding this matter.
Thank you.