Generally, research work is done by the group of researchers and they form a network called Research Professionals’ Collaboration Network, which acts as a social network. In social Network, the key nodes are defined by the centrality measures, while the key researchers in the research community are defined by the h-index. In this paper, the collaborative index, a combination of social network characteristics and the citation based index h-index has been discussed. The lobby-index, weighted network lobby-index, h-degree and c-index have been used to discover the key researchers in the community. © Springer Nature Singapore Pte Ltd. 2018.