While visiting Turkmenistan make sure you need to carry a lot of cash as in most of the places you need to do the cash transaction. Manat is the national currency of the country. The currency was first introduced in 1993 that replaced the Russian ruble. 1 manat= 500rubles
You can exchange your money to manat in Turkmenistan. If you are carrying US dollars you can make payment in dollars in some big hotels. You can withdraw cash from international ATMs in Ashgabat with a 3% withdrawal charge for each transaction. You can exchange the money in banks and Bureaux de Change.