Which two parts of Jharkhand were strategically very important for the British?

The east India company was frightened for its commerce due to the hostility of Mir Qasim and the marathas in the gangetic valley of Bihar and the santhal pargana, which was one of the key reasons for the British arrival in Jharkhand. When the British were obliged to pay tribute, the company executives were frequently harassed by the zamindars of south Bihar, and they sought refuge in the forests of Chota Nagpur and Palamu. The marathas were a significant threat to the company's western frontiers in Bihar, which made the strategic importance of the Chota Nagpur and Palamu for the British. As a result, they attempted to control these two regions' hills and forts.