B.Tech is a 4 year professional undergraduate degree. It revolves around planning, designing and building structures. B.Arch and Civil engineering are overlapping subjects. The major difference is that B.Arch concentrates more on the design aspect whereas Civil takes care of the structural part (i.e) on how feasible the design can be.
Bachelor of Planning (B.Plan) is a 4 year undergraduate degree which deals with professional planning. This course helps in the planning and management of urban and regional areas.
JEE Mains Paper-1 is the entrance exam for admission into courses such as B.Tech in various NITs (National Institute of Technology) and GFTIs (Government-funded Technical Institutes), IIITs (Indian Institute of Information Technology), CFTIs (Centrally Funded Technical Institute).