Minister of state Sanjeev Balyan was the third minister to quit from his post.
Some of those who have resigned, like Skills Minister Rajiv Pratap Rudy, are likely to be given organisational roles in the BJP, sources said, ahead of the 2019 national election when Prime Minister Narendra Modi will seek a second term. Minister of State Health Faggan Singh Kulaste may also step down, say sources.
Some ministers could lose their jobs over performance. Radha Mohan Singh has faced tremendous flak over the death of protesting farmers in Madhya Pradesh's Mandsaur, where the BJP lost a by-election to the Congress recently.
Resignations on Friday came hours after BJP chief Amit Shah met senior ministers at his Delhi residence. Mr Shah later met PM Modi.
Water Resources Minister Uma Bharti reportedly offered to resign on health grounds. Kalraj Mishra, who met Mr Shah yesterday, is well over 75, the age limit in the BJP for ministers.
The possibly last major reshuffle before the national election is expected before PM Modi leaves on Sunday for a BRICS summit in China. President Ram Nath Kovind will be away in Tirupati today and will be back only tomorrow.
Earlier on Thursday, minister of state Mahendra Nath Pandey was appointed the BJP's Uttar Pradesh chief, creating one more vacancy in the Council of Ministers.
Among the new faces expected to join PM Modi's team are at least two members of Bihar Chief Minister Nitish Kumar's Janata Dal (United), the BJP's latest ally. Sources said Tamil Nadu's ruling party AIADMK is not joining the union cabinet in this round.
The ruling BJP may also accommodate leaders like Bhupendra Yadav, who is in-charge of Gujarat, with an eye on elections in the state later this year. Prahlad Patel, a BJP leader from Madhya Pradesh, where elections will be held next year, could be inducted as a minister, sources said.
Finance Minister Arun Jaitley, who holds additional charge of Defence, is expected to shed one of the two key ministries. Responding to a reporter's question on Thursday on how long he would continue as Defence Minister, he said, chuckling, "At least I hope not very long."
Many expect a change in the Railways Ministry after a series of accidents. For the first time after two derailments within four days, Minister Suresh Prabhu met PM Modi and indicated that he had offered to quit but was "asked to wait".
Two key ministries opened up and were re-allotted after M Venkaiah Naidu was named Vice President of India. The Environment ministry was also reassigned to Harsh Vardhan as additional charge after the death of minister Anil Dave.