The chargesheet was filed before the court of special CBI judge P S Rana on Tuesday, CBI superintendent of police R Upasak said.
The two BRO officials were posted in Deepak Project of GREF at Shimla when the procurement was made four years ago.
The case against Brigadier Narang, who was posted here as chief engineer, Lt. Col. Jhamb and functionaries of New Delhi-based Siemens Enterprises Communication Pvt. Ltd. Was registered in February last year.
The exchanges were installed at the BRO offices in Himachal Pradesh and Uttarakhand.
CBI had carried out searches at the residence of Brig. Narang in Noida and allegedly recovered Rs 1.33 lakh in cash, more than Rs 30 lakh in bank accounts, Rs 15 lakh in mutual funds and ornaments worth Rs 5 lakh.
Documents having details of four plots, two flats and a two-storeyed building and two vehicles registered in the name of Narag and his relatives have been detected by the CBI, official sources said.