However, the Sena's demand for elevation of the existing ministers of state to the Cabinet rank was turned down by the chief minister.
Five Bharatiya Janata Party legislators will also take oath as ministers.
Uncertainty over whether Sena would be part of the cabinet expansion loomed large throughout Thursday as there was speculation that Sena will not become part of the exercise, as it was not given a single berth during the recent Union Cabinet expansion.
A close aide of Shiv Sena chief told PTI late tonight, "Uddhav Thackeray tonight said that Sena MLAs Gulabrao Patil and Arjun Khotkar will be inducted into the Fadnavis council of ministers."
According to the Sena source, Patil, legislator from Jalgaon rural constituency and Khotkar, five-time MLA from Jalna will take oath as MoS.
Several rounds of meetings were held at 'Matoshri' and 'Varsha', the residences of Uddhav Thackeray and Fadnavis respectively, to discuss about the party's stand over the cabinet expansion.
At the meeting of party legislators held at 'Matoshri', Uddhav finally decided to be part of the cabinet expansion.
"Several legislators were against joining the cabinet as the party was insulted by the BJP president Amit Shah before expansion of union cabinet. However, their voices were dominated by party ministers. The ministers succeeded in convincing Uddhav ji to accept the offer from CM," the Sena source added.
Senior Shiv Sena ministers Diwakar Raote and Subhash Desai, who attended Sena's meetings later also met the Chief Minister and tried to convince the latter about the party's demand.
"Thackeray's demand was that its existing MoS should be elevated as cabinet ministers. However, Fadnavis was not ready for that," a Sena source added.
Several meetings were also held between the officials after which the central hall of the state legislature was chosen as the venue for oath taking ceremony of new ministers.
The 20-month-old Fadnavis government will fill up portfolios rendered vacant after the resignation of senior minister Eknath Khadse over corruption charges last month.
The 10 portfolios handled by him are temporarily with Fadnavis.
"Gulabrao Patil's induction will boost the morale of Shiv Sainiks in Jalgaon district, where BJP leader and former revenue minister Eknath Khadse has finished Shiv Sena as well as opposition NCP from the district by using the government machinery," the close aid of Patil said requesting anonymity.
He added that the Sena will become stronger in the coming days.
"Patil is known as an aggressive speaker," he said.
Khotkar belongs to Jalna, the district from where BJP's state president Raosaheb Danve hails.
"It would be a political strategy of Sena to dominate BJP from the district as well as Marathwada region," said the Sena insider.
The chief minister had invited the BJP's probable candidates to meet him at 'Varsha' tonight. Jaykumar Rawal (Shinkheda, Dhule), Madan Yerawar (Yeotmal), Sambhaji Nilangekar (Nilanga, Latur), Subhash Deshmukh (Solapur South) along with BJP allies Sadabhau Khot of Swabhimani Paksha and Mahadev Jankar of Rashtriya Samaj Paksha attended the meeting.
The Maharashtra government under the leadership of Fadnavis has been functioning with a strength of 20 ministers and 10 junior ministers. Fourteen berths are still unoccupied.
Of the 30 ministers in Fadnavis' cabinet, 20 are from the BJP and 10 from the ruling party's ally Shiv Sena.
According to Article 72 of the Constitution, the number of ministers in the Union or state cabinet cannot exceed 15 per cent of the total number of members in the Lok Sabha or state legislative assembly.