Mechanical Engineering

Hi,
Actually it depends on which field you are interested upon. Both are related to travelling, so two of them have a good scope.
As you have done B.Tech, so you can surely opt for Masters. Both airport jobs as well as tourism has good career opportunity.
Being a very wide field, the scope of employment in tourism sector is very bright and the potential is still largely untapped. Career opportunities exist both in the public and private sector. In the public sector, there are opportunities in the Directorates and Departments of Tourism of the center and the state as Officers, information assistants, Tourist guides etc. Another good prospectus for qualified tourism professionals are in the private sector with travel agencies, tour operators, airlines, hotels, transport and cargo companies etc.
The opening up of the skies to private airlines and their emerging tie-ups with foreign airlines has removed bottlenecks in the transport and communication network resulting in easy flow of domestic and foreign tourists in the country. Since this is a new area of employment, not many qualified and experienced people are available and the promotion prospectus are also very bright and rapid. After a few years of experience, one can also start their own business by handling all travel requirements of a client and gradually building up business, taking on additional employees.
A degree in travel and tourism management equips you to work in such locations as a travel agency, a hotel, an airport, or any other hospitality-focused locale. Degree levels differ depending on the career, but all of these jobs require a certain subset of knowledge and the ability to multitask and communicate clearly with customers. Hence both have good scope for future. You can choose either of them based on your criteria of job and interest. I have given a brief overview of both above which you can refer and decide upon.
Hope it helps.