|Several decades of extensive observations have not revealed much on the nature of the central engine powering the GRBs as well as its jet composition, structure and viewing geometry. In an attempt to classify the physics of the GRBs, in a recent work, we have identified 8 long GRBs with black hole as their central engine and have inferred their masses to range between 2 - 60 solar masses. In the other part of the work, we have studied the prompt emission of a sample of short GRBs to infer the viewing geometry and its jet opening angles. Interestingly, we note that based on the current LIGO sensitivity, our study predict the rate of concurrent detections of bright short GRBs and gravitational waves to be 0.19 − 2.87 events per year. This is important to the upcoming joint observations by different multi-messenger international facilities.