Iran is a country located in South-Western Asia, it could be considered to be in every scenario, if you count nations like the Sasanians, or Timurids, however, if you don't count them, Iran is the same size on every scenario it is in.
This page, will only talk about modern Iran, including Qajar.
Qajar's first and only appearance is in the Victorian Era (1836). It is the 14th strongest nation, it has a ruler, Mohammad Shah his bonuses are: -1% Administration (Good), -2% Military Unkeep (Good), -1% Research (Bad). The country's Technology level is 0.41, Happiness level is 75%, and Stability level is 100%.
This is the first time Iran appears, also as a Democracy, in the WW2 Scenario. It is the 18th strongest nation, it has a ruler, Reza Shah who, isn't part of Mohammad's dynasty. He gives the following bonuses: +2 Population Growth (Good), +2% Economy Growth (Good), -1% Administration (Good), +2% Movement Points. The country's Technology level is 0.41, Happiness level is 74%, and Stability level is 100%.
Iran in the Modern Day Era is just like the World War Two Iran, except the leader has changed to Hassan Rouhani who gives the following bonuses: +1% Population Growth (Good), +2% Economy Growth (Good).