Sources told the council of ministers would be inducted after a three-day special Assembly session that has been called in the state capital Chandigarh on November 4.
It will take at least a week more for the induction of 11 ministers in the Cabinet, a senior BJP legislator said.
On the first day of the session, all 90 legislators will be taking the oath of office. On the second and the third day, there will be the Governor's address and the reply to his address, respectively.
Chief Minister Khattar and his deputy Dushyant Chautala, who held the first state Cabinet meeting on October 29, are yet to assume charge in the secretariat here.
Khattar and Dushyant took the oath on October 27 after a post-poll alliance.
The former is from the BJP, who is at the helm in his second stint, while the latter is leading his fledging Jannayak Janta Party (JJP), a defector of the state's once prominent regional outfit Indian National Lok Dal (INLD).
"Now the process is on to constitute a committee, comprising both BJP and JJP leaders, to formulate a common minimum programme ahead of the induction of council of ministers," said the BJP legislator.
Dushyant, the great grandson of former Deputy Prime Minister the late Devi Lal, won 10 seats in the 90-member house by wooing the youth for whom he promised 75 per cent reservation in private jobs and to reduce long distances that the unemployed have to travel for recruitment examinations.
The BJP came to power with a pledge to give an interest-free crop loan of up to Rs 3 lakh to farmers, besides setting up a Ministry of Youth Development and Self Employment and imparting skills to 25 lakh youth at an outlay of Rs 500 crore.
Sources said the JJP, besides the Deputy Chief Minister's post, has been eyeing crucial portfolios of Home, Finance and Excise and Taxation.
It is learnt senior BJP leaders like six-time legislator Anil Vij, who earlier was Health and Sports Minister, is not happy with the party's seat-sharing formula with the JJP.
He has been eyeing the Deputy Chief Minister's berth for his seniority.
The coalition government will have 13 ministers, including the Chief Minister and Deputy Chief Minister.
There may be some understanding of giving three berths to both the JJP and independents and the BJP wants to keep the remaining eight posts in the council of ministers, said a source.
The BJP won 40 seats and was six short of a majority in the 90-member Assembly.
Besides the JJP, seven independent MLAs have also extended support to the BJP, helping it reach a tally of 57 seats.
The Congress won 31 seats, improving its tally from 19 in 2014.
In a related development, the Haryana Congress Legislature Party (CLP) on Friday passed a resolution which authorised Congress President Sonia Gandhi to name the CLP leader.
Apart from state party President Kumari Selja, state in-charge Ghulam Nabi Azad and former Chief Minister Bhupinder Singh Hooda were also present at the meeting held here.
(Vishal Gulati can be reached at vishal.g@.in)
( With inputs from IANS )