Hi Brij,
Currently, I am living in Canada. I am sending 80,000-100,000INR every month to my dad's account. Who is living in India, Whatever money I am sending to him from my side is after tax. So, my question to you is how much money I can send to his account. So, they do not need to pay any tax to the Indian government?

Trust: You can set up a trust in India, with your nephew as the beneficiary, and transfer the money to the trust. The trust can specify that the money will be vested in your nephew after 4 years. This can be done with the help of a lawyer or a professional trust company.

If you want to send money securely to India but don't want to do so over the Internet, a money order is a great option. A money order is a printed, pre-paid certificate that can be mailed to your Indian recipient for cashing. Money orders can be purchased at banks, gas stations, grocery stores, the post office, and other third-party locations.

A good rule of thumb: never send money from the US to India with banks, Paypal, or cash-based money transfer services. Sending money with them is very expensive if you calculate all the fees (including hidden currency exchange rate margins). However, there are also plenty of other options to send money from the US to India. You can compare on Monito and find the cheapest money transfer operator for your next transfer to India.

Is there any restriction in the use of that capital by the receiver, or, once transferred, the NRI son or daughter is free to use it for any legally permitted purpose abroad.

You are a CA so I can't even say talk to a CA. My understanding is as this property is in India, your brother should be in India to transfer this asset to you - you should talk to a lawyer in your city development office where property registrations happen.
If I assume son is major - in that case, there are no tax issues in India. But to show that transferred amount was a gift - one can write a simple gift deed.
When you send money to India from an online remittance agency, you will not be required to pay taxes on that amount if you are an NRI. However, if you are not an NRI then you will have to pay taxes on the global income. In this case you can always ask for a claim against the tax you have paid overseas.
_{Step 1: Simply enter an amount. Step 2: Provide your recipient's name, address, and phone number. Step 3: Select a convenient location for easy cash pickup, including Muthoot Finance and Manappuram Finance. Step 4: Easily pay with Paypal, bank account, credit card, or debit card. View all cash pickup locations}
information service that aims to provide you with information to help you make better decisions.