Hi
IT BHU Chemical should be preferred , as firstly it gives u the brand name IIT and secondly Chemical is a good branch and are offered good jobs and better packages. IT BHU is an established institute and has been recently named IIT , but it has gt fine infra for a good accademic development. Although BITS is a world class institute , but it does nt offer u the brand name IIT . 
Also chemical engg. has got great scope in India. Since Chemical engineering is a vast field, the job prospectus and career options of a chemical engineer is varied and different. Chemical engineers play a key role in industries, mostly in the manufacturing field. Their work area varies from petroleum and petrochemicals to food, materials, specialty chemicals, plastics, power production, environmental control,waste management and biotechnology.  



As it is a varied field Chemical engineers could specialise in a particular chemical processess such as oxidation or polymerisation or in a specific product such as plastic or rubber. Besides designing equipments and plants, testing manufacturing processes and supervising production; they also study the properties and effects of dangerous chemicals, device process of neutralising them and also on the development acceptable substitutes. As such their work can be dangerous.  

Wide employment oppurtunities await chemical engineers both in the public sector as well as the private sector. They can seek jobs in areas such as processing, operations or manufacturing, research and development, design and construction, finance and teaching. They may also pursue a management degree after B.Tech and take on marketing jobs. Candidates with an additional management degree are sought by private industries. In process industries they could work in positions such as a supervisor or manager, technical specialist, project manager or project engineers. 
Among the manufacturing industries, pharmaceuticals provide the best opportunities for chemical engineers. In the government sector, chemical engineers are employed to solve environmental problems such as waste and water treatment, environmental regulations and recycling; on energy sector such as energy conservation and research on alternate energy sources and health-related research projects, defense establishments and atomic power plants. They are also employed in service industries such as scientific research and development services, particularly in energy and the developing fields of biotechnology and nanotechnology. 
Other work areas of chemical engineers include food processing, coal preparation and mineral processing, explosives manufacturing, chemical process industries such as fertiliser industry, including pesticides and herbicides, caustic soda, glass and specialty chemicals, dyes and dyestuff, paint, lubricants, steel and aluminum production. They are also employed in a variety of manufacturing industries other than chemical manufacturing, such as those producing electronics, photographic equipment, clothing, pulp and paper and even in the development of aircrafts.