Iran is visa-free for Indian tourists, but booking a flight is bumpy
First, have a look at the conditions under which you can travel visa-free to Iran:
2. The visa exemption only applies to anyone visiting iran for tourism purposes.
3. If indian citizens intend to stay for a longer amount of time, make repeated entries within six months, or require other sorts of visas, they must get them from the Islamic Republic of Iran's separate representatives in India.
4. The visa elimination described in this permission only applies to indian nationals who enter the country via air data-border.
What about flights from India?