Drilling and blasting method of excavation is a preferably suitable method for excavating quartzite and schist rock mass exhibiting class II. However, it is associated with many hazards like ground vibration, air overpressure, fly rocks, etc., in absence of controlled blasting. An open trial blast with the drilled hole diameter of 100 mm and maximum charge per delay (MCD) 30 kg carried out by the site personnel had already reached at an alarming level in terms of fly rock and excessive throw of the fragments. Hillock excavation in such open space with other multiple operational workings, the fly rock, and the throw of the blast fragments were the most considerable hazards due to uncontrolled blasting. These challenges were then handled by CSIR-CIMFR with controlled blasting techniques. A controlled trial blast using the muffling technique to arrest the fly rock and restrict the throw of the material in a very limited space was found to be efficient and further excavation of the hill was done in a controlled manner. It could be achieved with the help of good muffling technique along with short drill-hole diameter (32 mm) and depth (1.5 m) and MCD under 2.50 kg. This case study is pertaining to a work of four lanning of the Barhi-Koderma section of NH-31. The study site is adjacent to a running railway track connecting Hazaribagh to Koderma. A hillock with approx. width of 20–25 m, length 80–85 m, and height of 25–30 m exists between the highway under construction and the existing running railway track. Thus, removal of the hillock is very critical and challenging. This work is being carried out using technical expertise and supervision of CSIR-CIMFR without disturbing or damaging the railway traffic. The full-length paper covers detail of the project site and blast design for controlled blasting with monitoring results and analysis.