It's extremely important for NRIs as well as Indians travelling on a short duration visit abroad to understand the amount of currency that they are permitted to bring into India.
An NRI coming into India from abroad can bring foreign exchange without any limit provided if foreign currency notes, travellers cheques, forexplus card do not exceed US$ 10,000. If the same exceeds $5000 by way of currency then you must inform the Customs Authorities at the Airport in the Currency Declaration Form (CDF), on arrival in India.
In fact, before their visit they could remit money into their NRE or NRO account and then use the same for their expenditure while on a trip to India. This is much better than carrying foreign currency or travellers cheque and then encashing the same here into rupees. You would unnecessarily incur extra charges for conversion of the currency as well.
How much Indian rupees can you carry?
In the case of Indian rupees, NRIs or other Indians travelling back to India from a visit abroad, can carry into India, currency worth Rs 7500 only.