Iran was not a Muslim country.

Iran i.e. Persia, was Zoroastrian country in 600 BC year. Persians or Parsi people migrated to India (Tatas are Parsi from Persia). Main religion of Iran was Zoroastrian.

1) In 600 BC year, Zoroastrian religion existed in Iran (Persia).
2) In 1 AD year, Christianity was born.
3) In 600 AD year, Islam religion was born.
4) In 650 AD year, Islam religion started spreading in Iran.

The "minorities" started "converting the majority" of population of Iran from Zoroastrian religion into Islam.

Parsi people ran out of Iran to save their lives. Hindu king of Gujarat allowed Parsi immigrants to stay in India(Hindus never kill people unnecessarily). The Tatas are grateful that Gujarati people welcomed Parsis when their own country threw them out.

Today, due to religious conversions, Iran became Islamic country.

(Parsis never shout "Free Iran", just like "Free Palestine". Parsis live happily wherever they are, even though Iran belongs to Zoroastrian people)