Compare exchange rate, costs before sending funds abroad

There are several RBI-licenced money changers who offer remittance facilities that you can consider

Your child has secured admission to a university in the US and is preparing to fly abroad for the spring term. One of the things bothering you is how to send the money. In  addition to the tuition fees and other college-related expenses, money is also required for day-to-day expenses. How much money can you send? Is it better to send it through a bank? Will an authorised forex dealer give you better rates? Is a forex card a good option?
 
Under the Liberalised Remittance Scheme (LRS) of the Reserve Bank of India (RBI), an individual can remit $250,000