If you were not to provide them with the correct SIN , how will the Indian Banks validate its correctness ?

Provide a nine digit number to them as SIN .. Most likely its just an eyewash and they would be satisfied .

If not then maybe they will come back to you in a couple of years IF CRA shares info with them which is highly unlikely (CRA doesnt have enough staff and resources) - if some how they come to know through CRA about your SIN , then you always admit a mistake later.

Till then ... sleep after submitting the 9 digit number.

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Fido.

If you are worried about past years & not reporting interest from past years & CRA catching you.

Then just close down both the NRO/NRE accounts with that particular Indian bank of yours & open a new account with a totally new bank with whom you never had a bank account before . There are countless banks in India, pandering to NRI's as they need foreign exchange.

So now you are starting fresh from 2018 on wards. Then going forward report your interest from 2018 from the Indian bank to CRA if you are worried about it.

Keep most of your money in NRE & very little in NRO. NRE will have NO TDS & nothing to report with either India IT dept or CRA.

Only whatever you get in India keep it in NRO as you can't deposit that in NRE. But whenever you send any money from Canada to India, always send it to your NRE and not NRO account.

You can always transfer money from NRE to NRO, but NOT from NRO to NRE.

CRA is doing nothing about PANAMA papers.

They are doing nothing about countless Canadian rich people who have millions & billions in off shore TAX HAVENS like lot of the Carribean Islands like Bahamas etc.

Even Big companies & corporates are avoiding taxes by routing money over seas & avoiding taxes.

In Canada itself there is a HUGE underground economy mostly in Construction, Trades, Restaurants, Farming, where cash jobs are done & cash invoices are done so NO HST is charged.

I myself paid a guy to do my basement in cash. If invoice or check payment is required he was going to Charge me 13 % HST. Same when I did my Patio Pavement , paid in cash, no tax , no HST.

Do you really think CRA has the time to go after some Desis Interest in Rs. on his NRO/NRE Indian bank account ? After converting that in CAD dollars, its a paltry amount.

We are not talking about the principle amount which could be BIG, but just the bank interest on it.

They have bigger fish to fry

Thanks Mitron, Full House, Fido for your input