Station House Officer, Inspector Sandeep More, said that they have solved the murder case of Harbir and arrested two main accused Krishna Khatana and Surender.
Krishna was nabbed from Sector-21D and Surender from Ajronda, the SHO said.
Four more people were involved in the murder and a hunt was on to nab them, he added.
During interrogation, the duo disclosed the names of two of their accomplices Abhishek and Yogesh Pahalwan, More said.
Krishna said he runs a real estate business and was working on commission basis with Harbir. He developed a dispute with Harbir over issues related to payment and thus decided to get rid of him, police said.
Harbir was shot dead at point-blank range on September 28. He was rushed to nearby Sarvoday Hospital where he was declared brought dead.