Lot of research has been carried out in the field of integrating MANET with Internet. The main challenge in this direction can be grouped into four categories: addressing, routing, gateway and mobility issues. Of these, the Gateway has grabbed the attention of most researchers as it is dual interfaced and serves as a liaison between the mobile node in the MANET and the fixed node in the internet. This paper focuses on a trust based Hybrid Gateway selection scheme. Several Gateway selection schemes were proposed that uses either single or multiple metrics that employs only the Gateway related metrics such as mobility, residual energy, etc. These schemes doesn't guarantee that the path established with the Gateway is secure as the path may include numerous malicious nodes or selfish nodes or even congested nodes that may drop the packets it receives without forwarding. To overcome this situation and provide an end-to-end security, it is necessary to select a Gateway that can be reached via trusted nodes and uncongested route. In this paper, we propose a Gateway Selection scheme that considers a normalized security metric employing multiple security parameters such as node trust, route trust and residual route load capacity to select an optimal Gateway candidate node. The precise estimation and Gateway selection employing this normalized security metric are detailed in this paper.