Certification

Hi Sonu,
You should not get too fascinated with ethical hacker as they show in movies. Most of the institutes provide just a basic fancy course under the name of ethical hacking, just to attract students and earn more.
I would rather recommend you to go for security specialist professionals. These jobs are highly payable and in high demand as most companies need them to protect their own data. These jobs work on the same logic that the best thief can protect the data in the best way.
For the same, you can go to some reputed computer training institutes like NIIT, etc. You can go for Java courses followed by networking courses and CCNA/CCNB (CISCO) courses. After this, you can also opt for CEH (Certified Ethical Hacker) certification courses, if you wish to.
You can go for these courses in NIITs or any other reputed computer coaching institute. However, I would suggest you to pursue these courses alongside B.Sc (Computers), BCA or B.Tech for better job prospects.
I hope it helps.

Cabin crew is a term used for the members of an aircraft crew, who attend the passengers. Some institutes offers job oriented courses, which helps you to prepare for cabin crew interviews. These are professional training, which doesn't require any certification from any university. They train you as per the airline criteria, so that you can crack the interview.
Training is not compulsory to face any interview. If you think you meet the criteria required by any airline, then go and attend any walk in interview. Once you face the interview, you will get an idea whether you need to join any institute or not for training.
You can check the below mentioned link:
https://www.shiksha.com/getListingDetail/107699/course/course-Diploma-In-Basic-Cabin-Crew-Services-And-Hospitality-Management-Chandigarh-India
All the best.