If you are an American, you are allowed to bring cash from your country to India as long as the total value does not exceed $5,000 USD. Same applies to all other foreign nationals, by converting this amount into your respective currency and complying with the law. If you are carrying more than the mentioned amount, you will have to declare it at customs. Also, note that the amount we have mentioned is for foreign currency. In case you are carrying Indian Rupees, the value should not exceed INR 25,000. Rest assured, there are ATMs (money vending machines) everywhere in the country, even in small towns. So, you can reliably and quickly get Indian currency any time you need it.