Police said Suresh, 43 and Kapil, 27 who were kidnapped by the accused in Bihar, were safely rescued from the state on Wednesday morning.
The kidnappers, identified as Ranjit, 37, Sanjeet and Pintu Kumar, all residents of Bihar, and Ayub Khan, of Delhi, were arrested from Bihar and Delhi in different police raids.
Both the brothers left for Patna by a flight on October 21 evening to meet a client who had offered them a huge contract for stone work (inlay) at a construction site in Bihar, said Joint Commissioner of Police, Crime, Ravindra Yadav.
They later informed their family members that they have been kidnapped by Maoists, and a ransom of Rs 4 crore to release both of them was also made by the accused to victims' family members, he said.
"On a tip-off, police teams raided Hazira Colony in Chattarpur (in south Delhi) and arrested Ayub Khan, one of the gang members," Yadav said.
Khan also worked as a labour contractor for stone inlay works, police said.
During sustained interrogation, he provided crucial clues in the case and hideouts of his other associate, Ranjit.
Later police also arrested Pintu Kumar and Sanjeet from Bihar on Ranjit's tip off and rescued the brothers from their clutches, Yadav said.