The Republic of Kalmykia is a federal republic (imagine state plus) in Russia. It is located north of Chechnya and it borders the Caspian Sea. It is also the only Buddhist-country in Europe. The Kalmyks are descended from the West Mongols and even further down the line they were a part of the Mongol horde. In the 1600s the Kalmyks accepted Buddhism of the Tibetan variety. Both the Tsar and the Communists tried to suppress the Kalmyks way of life with only moderate success. Today the largest Buddhist temple in Europe is located in Kalmykia.
This one is a tricky one. Depending on how you ask, South Korea is either has a Christian majority or Christainity comes in second to agnosticism. While historically Buddhist or Eastern Philosophical, Christianity has been spreading like wild fire in the South. Protestantism like Methodism, Presbyterianism, and Pentecostalism along with Catholicism are the main branches. South Korea comes in second only to America in the number of missionaries it produces. The largest single church (congregation-wise) in the world is the Yoido Full Gospel Church. Interestingly, two-thirds of all Christians were in the north before the breakup in 1945. Kim Jong il's father, Kim Il-sung was raised as a Christian in the heavily Christian-minority city of Pyongyang.
Suriname is the least populated country in South America and is wedged-in between French Guiana and Guyana. The Creole, Mixed, and Black populations generally are either Catholic or Moravian Protestant. A plurality of Surinamers are however Hindu. Many Hindustanis from the northern rim of Indian migrated to Suriname to work on the Dutch plantations after slavery was completely done away with in the 1870s. A majority of Surinamers are either Hindu or Muslim.