India, as a ‘developing’ country, is in the middle of a unique situation of handling its energy transition towards carbon-free energy along with its continuous economic development. With respect to the agreed COP 21 and SDG 2030 targets, India has drafted several energy strategies revolving around clean renewable energy. With multiple roadblocks for development of large hydro power capacities within the country, the long-term renewable goals of India focus highly on renewable energy technologies like solar Photo-Voltaic (PV) and wind capacities. However, with a much slower rate of development in transmission infrastructure and the given situations of the regional energy systems in the Indian subcontinent, these significant changes in India could result in severe technical and economic consequences for the complete interconnected region. The presented investigations in this paper have been conducted using ATLANTIS_India, a unique techno-economic simulation model developed at the Institute of Electricity Economics and Energy Innovation/Graz University of Technology, designed for the electricity system in the Indian subcontinent region. The model covers the electricity systems of India, Bangladesh, Bhutan, Nepal, and Sri Lanka, and is used to analyse a scenario where around 118 GW of solar PV and wind capacity expansion is planned in India until the target year 2050. This paper presents the simulation approach as well as the simulated results and conclusions. The simulation results show the positive and negative techno-economic impacts of the discussed strategy on the overall electricity system, while suggesting possible solutions.