This is the 1 Rial note from Oman issued in 1977. The front has the the national symbol of 2 crossed swords with a dagger (khanjar). The reverse has the Rustaq Fortress.
The note above is a 50 Kopek note from 1915 which was released by the Russian small note treasury. This is a pre-revolutionary note from Tsarist Russia.
The note has writing in the Cyrillic alphabet. More info on the Cyrillic alphabets HERE