If you have no problem with KYC/AML, it will be easier then. Is there any trusted and big local exchange in your country? I'm sure that there are some.
Here, I may suggest you research Kraken and also Coinbase, but not Coinbase pro. They offer high limits and also speed. For local exchanges, there will be speedier commonly, moreover withdraw it for fiat directly by wire bank.
Also what would be the tax implication of this? I purchased btc out of country. Wanted to do this to bypass FX control of my home country. The total amount is around 10 btc but wanted to do this over one year or so in small amount each time.
If your mind, you can read about the crypto taxation in the US in the following link. There is clear explanation about it.
https://koinly.io/guides/cryptocurrency-tax-guide/How about Bitcoin ATM's ? you can withdraw your BTC anonymously.
It may be, but the fee is very high if using BTC ATM. He must also compare the efficiency or speedy with the fee to make the transaction clear enough and of course, not wasting much money only for fees. moreover, it is high amount of BTC.
Does Bitcoin ATM's also buying Bitcoin or you can sell your Bitcoin in some Bitcoin ATM's? I thought it is only for buying Bitcoins.
Commonly, BTC ATM is used for buying BTC. But, there are also some BTC ATMs that offer the bi-directional functionality to buy and sell using BTC ATM. But of course, he must find the ATM correctly and think about the very high transaction fees if using the BTC ATM.