Hope I can be of assistance:

Yes, there are plenty of Bitcoin ATMs in Russia, this will be the most simple solution, they could simply pay the high fee and get the cash quickly:

Yes, there is BItrefill in Russia, although not many options for things to buy locally, but online services, VoIP, games and flight tickets

.

Another possible solution would be a Centralized Exchange that operates in Russia, I did a quick search and found https://www.bynex.io

This exchange is Belarusian and most probably accepts Russian citizens to open accounts, in their web page explains that they support wire transfers in USD, EUR, BYN and RUB among other currencies. They have an android app

I will suggest his brother opens an account in that centralized exchange with his mobile as it will do with a bank account but easier, pass the KYC, using your guidance to do so. Once that is done, the money can be wired in USD or deposited in USDT and keep the balance in USDT and exchange it (trade it) for RUB when needed and once that is done, perform a withdraw to their Russian Bank account using a wire transfer with IBAN.

The web site of bynex has contact address with email and telegram, I will suggest you get in touch with them and explain them the situation, they will tell you better than I can what you can and cant do with their exchange,

Best of luck!