Is it legal to buy cryptocurrency in USA and sell in India?

Hello, As there are some arbitrage in cryptocurrency exchanges in USA and INDIA , is it legal to send USD to friend in USA and let her buy bitcoin over there and tell her to send those bitcoin to your wallet and later on sell these bitcoins in India? Scenario is , Lets say I transfer 100$ to her US bank account. She buys bitcoin in US crypto exchange and transfer those bitcoins to my wallet. I encash those bitcoins and lets say I get INR equivalent to 105 $ . Then 1. Do I have to pay tax on 105$ or the 5$ earned? 2. And how I can link my 100$ transfer to my friend and 105$ gained by selling bitcoin? 3. If above scenario is possible then what are the documents I will need to support it ? The thing is my friend is buying bitcoin in her name as only US bank account holder can buy cryptocurrency in US Crypto exchange. and after transferring to me I am selling it and encashing it in my Indian bank account. I am using same bank account for transferring money to her and selling bitcoin. So is it legal and I am confused about the amount on which I have to pay the tax. This question is answered previously, I just want to know the scenario right now.