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You don't need any of these institutes.
Institutes like these wouldn't make much of a difference while you apply for an airline.
Every airline has their own training, and they don't care or give any additional priority if you have been in one of these institutes. Airlines have about 4-7 weeks rigorous training, with highly qualified instructors.
It's simply a lot of money for no good reason, the hype around these institutions are simply ridiculous.
You rather focus on being the perfect candidate for the job, and this can absolutely be done at home. We have the Internet to get all the information in the universe that we need, and trust me, that's all we need.
It is better you don't go for any institute first, attempt some interviews.

SRCC offers the graduation degree in two streams Commerce and Economics. The college does not have a separate admission process and follows the University of Delhi (DU) admission schedule to select the candidates for B.Com (Hons) and B.A. (Hons) Economics programs. There is no entrance exam for the B.Com and BA Eligibility.
The interested candidates need to have 10+2 certificate of CBSE/ISCE board or an equivalent with the minimum 45% marks in aggregate. The candidates must pass in five subjects, including four elective subjects and one language. The candidates having qualified the pre-university examination, i.e. 2 years after 10 years of schooling, or Intermediate Examination from a DU recognized Indian university are also eligible to apply for admission. More details can be found here https://www.shiksha.com/accounting-commerce/course/m-com-shri-ram-college-of-commerce-maurice-nagar-delhi-53148.