One of the nine also included a pact for avoidance of double taxation.
Following the meeting, MEA Spokesperson Raveesh Kumar said, "Both leaders held a substantive and productive discussion on cooperation in trade & investment, energy, connectivity, defence & security & regional issues".
"We will also hold talks with Indian officials on worldwide and regional issues", president added.
India today sought from Iran a stake in a producing oil field and said it will raise crude oil import from Iran in the financial year beginning April, reversing the 25 per cent reduction it had done in the current fiscal.
India has been a key purchaser of Iranian oil and gas, and maintained trade ties even as worldwide sanctions were imposed on Tehran over its nuclear programme between 2012 and 2016.
The Shahnameh, or the Book of Kings, the oldest Persian epic composed by the Iranian poet Hakim Abul-Qasim Ferdowsi Tusi (born in 940 CE, completed Shahnameh 1010 CE), has mentioned India in it more than 100 times, indicating the historical and cultural importance of India among Iranians.
Pak Army chief in Kabul to attend military talks
Pakistan has urged Afghanistan to stop the blame game and asked for its co-operation in combating terrorism. "Collaborative approach and persistence is the answer to all challenges".
According to the agreement, India will invest the money to build the capacity of Chabahar port.
Modi and Rouhani also released a joint postage stamp depicting the Kandla port in India and the Chabahar port.
Modi said that the talks also focused on people-to-people exchange, while noting that this continues between the students and intellectuals of the two countries. India followed the U.S. at the IAEA and voted against Iran and also cut energy trade significantly after the vote.
"We are ready for trilateral and multilateral contracts so that this transit route through Chabahar Port turns into a strategic route to consolidate regional ties", said Rouhani, as he and Modi jointly addressed media-persons after the meeting.
It said both sides "endorsed UNGA consensual resolution in 2013 derived from the idea of Iran's President World Against Violence and Extremism (WAVE)" and called for combating terrorist elements and complete eradication of their supportive movements, cutting financial support to terrorist groups in particular.
Rouhani also met India's Minister of External Affairs Sushma Swaraj.
Sushma Swaraj described the visit of senior Iranian and Indian officials to the capitals of the two countries as the sign of high level of relations, and said: "We hope that the two countries' relations will develop in all fields of mutual interest".