The limit to transfer funds from your NRI accounts in India to your overseas account in USA vary with respect to the types of accounts chosen for remittance:

Limit of transfers from India to USA

NRE Accounts: There is no limit for repatriating funds from NRE accounts as it is fully and freely repatriable from India. NRE Deposits are tax-free in India as NRE Accounts are meant to maintain the income earned outside India.

NRO Accounts: The maximum fund that you can repatriate per financial year from your NRO account is USD 1 million as allowed by Reserve Bank of India (RBI). The funds are not freely repatriable. The interest earned on NRO Deposits is taxable in India: 30% tax + surcharge + education cess* is deducted at the source of interest earned in India for everyone. 

However, you can later claim for a tax refund according to your tax slab:

You can also transfer funds from NRO to NRE account after providing proper documentation prepared by a Chartered Accountant stating that all the taxes are paid on the funds being transferred from the NRO Account. 

For discussing the same with a CA, you can get Tax advisory from SBNRI experts from the link below. Just write your query and we will get back:

Ask SBNRI Tax Expert Now

FCNR Accounts: There is no limit for repatriating funds from FCNR accounts as it is fully and freely repatriable from India.The FCNR Deposit lets you earn tax-free interest on most of the major globally tradable foreign currencies such as USD, GBP, EUR, JPY, AUD, CAD, SGD, HKD, and others.

*(Cess: A cess is a tax on tax that you pay to the government for purposes set by the government. The cess is charged till the objective set by the government is fulfilled. Eg: Krishi Kalyan Cess, Swachh Bharat Cess etc.)