If you want to join the aviation industry quickly then go for a short Diploma or Certificate course in Airport Management. In India many institutions offer a duration of 6 to 12 months for certificate or diploma level course.
But if you want more in depth knowledge and better long term career growth then a bachelor's degree such as BBA in Airport Management with 3 years duration may suit you better.
In a short Airport Management course over 6-12 months you learn basics like airport operations ground handling passenger service cargo management aviation safety and security and customer service.
This is good if you want to start working soon in ground staff airport operations cargo or customer service roles. You get practical training and basic knowledge.
A longer 3-year course gives you deeper study. You not only learn airport operations and safety but also management aspects logistics regulatory rules aviation law and more. This means you are better prepared for higher responsibility jobs.
Because you spend more time you also get better soft skills communication and understanding of various airport functions which helps if you aim for growth and long term career.
Ask yourself
Do I want to start working soon or do I want a stable long-term career in aviation
How much time can I invest now - a few months or several years
What level of job I aim - entry level ground staff or managerial role
If you want quick entry and to start earning soon a short 6-12 month course is fine. If you want stronger foundation and better growth go for 3-year degree.
Also check what institutions offer and what their syllabus includes. If institute gives good practical training and exposure even a short course can work well.