B.Com

B.Com. is a graduation degree course, and Cabin Crew course is a professional training. It will not add to your education, but it will help you get trained for a particular job role.
Hence there is no harm in doing both simultaneously.
For your convenience, I've listed below the general guidelines and requisites for becoming a cabin crew member.
In general, candidate's profile for freshers for cabin crew is as under-
Age: Between 18 and 27 years
Minimum Height: Men - 170 cms and Women - 157 cms
Weight: In proportion to height
Educational Qualification: HSC (10+2). Candidates who are appearing for their HSC examinations can also apply.
Physical features: Pleasing personality, clear complexion (scars, pimples and blemishes not acceptable) and good eyesight
Marital Status: Unmarried
Language skills: Fluency in English and Hindi. Proficiency in a foreign language will be an added advantage.
Interactive skills: Excellent communication and good interpersonal skills
Nationality: Indian citizens only
Passport: Must possess a valid Indian passport or should have applied for a passport
Mandatory Documentation: Must possess a Pan Card and Aadhaar Card
So that becomes very clear that it merely requires some grooming to get the job of a cabin crew. They don't demand much from the candidates.
You should be interpersonally sound and capable to handle people from different cultures.
Cabin crew is the face of the airline.
Foreign languages like German, French, Russian, Arabic, Chinese and Japanese, etc. can allow you to get an edge over others, as this allows the airline to roster you on routes where such languages are spoken.

Eligibility criteria- Passed 10+2 examination with five subjects of 100 marks and English as a subject and any one of the following: Accounting, Business Economics including Business Mathematics, Business Organization, Mathematics, Business Mathematics, Economics, Statistics, Business Studies, Office Practice and Secretarial, Financial Accounting, Elements of Cost Accounting and Auditing, Book Keeping, Commerce, Cost Accounting and Principle of Management with minimum 75% marks in aggregate.
Goenka College of Commerce and Business Administration invites candidates for B.Com (Hons.) in Finance and Accounts who have passed 10+2 examination with relevant subject with 75% marks in aggregate. However, for OBC candidates, the minimum score must be 67.5% marks while the SC/ ST candidates are required to have 56% marks in aggregate.
Good luck Madhurima.