It is unclear what is being asked here.
If what is meant to is to ask about the COUNTRIES (note the "r") to the east of Iran, those would be, from north to south: Turkmenistan, Afghanistan, and Pakistan.
If what is meant is to ask what are the easternmost counties (shahrestan in Farsi) of Iran, they are from north to south: Sarakhs, Torbat-e-Jam, Taybad, Khaf (all in Razavi Khorasan Province), Zirkuh, Darmis, Sarbisheh, Nehbandan (all in South Khorasan Province), Zabol, Zahedan, Khash, Saravan, Sarbaz, and Chahbahar (all in Sistan and Baluchestan Province).
The countries that lies to the east of Iran are Afghanistan, Pakistan, and Turkmenistan.
Iran is east off the eastern coast of Saudi Arabia, but between Saudi Arabia and Iran lies the island-nation of Bahrain.
Russia, Kazakhstan, Uzbekistan, Turkmenistan, and Iran does.
Turkey's easternmost border is shared between Azerbaijan and Iran.
Iran
The country in the region that lies farthest to the north in the middle east is Saudi Arabia. Saudi Arabia is the largest Arab state at approximately 870,000 square miles.
Norfolk and Suffolk counties are the furthest east of the British counties.
The Zagros mountains can be found in western Iran and separate the plains of Assyria and Babylonia from the Iranian highland.
Pakistan has 4 neighboring counties. China is in the north. Iran and Afghanistan are in the east. India has the longest border in between India and Pakistan.
India is found directly east of Pakistan, except in the far north of the country, where heading east would bring you into China.
South East Counties League ended in 1998.
Iran is the country that lies between Iraq & Pakistan. Iran's historical name was Persia, though it did not have today's borders as those were defined in the 18th and 19th centuries.
Most say that Iran is in the Middle East, but there is a minority opinion that says that it is not. Regardless, Iran is not an Arab country.