Hydrogen embrittlement includes the mechanisms by which hydrogen is diffused into a system and causes mechanical degradation by loss of ductility. Therefore, in metals including Fe, selective alloying is used for strengthening and reducing the diffusivity of hydrogen by formation of precipitates or intermetallic phases which act as potential trapping sites. We have performed ab initio calculations focusing on the interactions of substitutional (Al, Mn) and interstitial alloying elements (B, C, N) commonly used in austenitic steels at grain boundaries. Our calculations helped us to identify alloying elements with the highest stabilising power. This is quantified by the calculation of thermodynamic parameters such as segregation and embrittlement energy. We have then compared these parameters in presence of hydrogen. Our systematic investigation enables us to understand the basic mechanism of hydrogen interaction with defects in alloys. Identification of such trends in presence of hydrogen can guide experimentalists in the choice of alloying elements and ultimately advance materials design.