To purchase USDT for rubles, use USDT exchangers
USDT/BUSD Calculator Tether to Binance USD
Price of 1 Tether today (4 June)
BUSD 1.017
-0.0149%
USDT 
BTC
USD
RUB
EUR
GBP
ETH
LTC
BCH
BNB
BUSD
SOL