Hello Friend,
Don't be upset as you can't get into army always remember one thing in Life"The Past has no Value but to fuel a more BRILLIANT TOMORROW." Congratulations for completing your B.com . As you have said that basically you are outdoor person who loves traveling than definitely you can make your hobby or passion your profession. How we can make your Outdoor Traveling into a fruitful career lets have a look to it:

Let me come square to square:
Difference between PGDM and MBA:-
PGDM:
PGDM means Post Graduate Diploma in Management. Students often get confused whether its a Diploma course or a Degree course and they land up taking decision many a times not to go for PGDM course.However,Students are correct to some extent that its a Diploma course but many of them do not know why its called PGDM. When an institute is an autonomous body i.e not affiliated to any University and conducts there own independent management courses than they are called PGDM as they cannot offer MBA degree.Many of the premier institutes offer PGDM institutes like IIM's,XLRI etc. AICTE(All India Council for Technical Education) allows approved colleges to offer PGDM courses. The plus point of these courses is the institutes design their own curriculum and students learn the new things instead of following outdated syllabus of University.While opting an autonomous college make sure that it is an AICTE approved.

MBA:
MBA means Master in Business Administration. Its a Post graduate degree offered by the colleges that are affiliated to Universities. As earlier said only University affiliated colleges can offer an MBA Degree.

CAREER PROSPECTS:-
Travel and Tourism:
The tourism sector of India is the largest revenue generating industry in the country. India being diverse country in terms of geography,culture,language etc. The scope for tourism is very wide.

After completion of Travel and Tourism you can make your career in Aviation,Shipping,Tourism,Hospitality.
You can get hired in some of the private companies like Thomas Cook, Cox & Kings, IRCTC, SOTC, Le passage, Make My Trip.Depending on your specialization you can also become a Tour operator, Ticketing Officer, Adventure Tourism Expert,Event Manager,Holiday Consultant.

You can even start your Travel and Tourism Company.

Hotel Management:
After completing your MBA in Hotel Management you can make your career in Front Office,House Keeping,Food and Beverage service in Hotels viz. Taj Group,Oberio, Welcome Group & etc. You can also do your career in Airlines as Cabin Crew,Ground staff or Public Relation Officer.
You can also get into Retail Sector performing Back Office Job or can do a teaching job in IHM colleges or can also startup your own venture and become ENTREPRENEUR. Can also become a consultant for building hotels or restaurants.

Colleges:

Travel & Tourism:
In order to get admitted for PGDM in Travel and Tourism one must have 50% aggregate Marks in his Graduation. Top colleges for the course are:
1.Indian Institute of Tourism and Travel Management(IITTM)
2.Sir Vithaldas Thekrsey College of Home Science
3.Department of Tourism of Hospitality of Heritage Studies, Jamia Milia Ismalia University.
4.School of Tourism Studies(Mahatama Gandhi university)
5.Department of Tourism Studies(Christ University)

MBA in Hotel Management:
In order to get admitted for any MBA degree you must have 50% aggregate marks in graduation and you must have given entrance exams like CMAT, ATMA, NMAT,SNAP etc.
Top colleges are :
1.Gujarat Institute of Hotel Management.
2.Hotel and Catering Management Institute,Chandigarh.
3.Achariya School of Tourism and Hotel Management,Puduchhery.
4.Biyani School of Science and Management,Rajasthan.
5.Coimbatore Institute of Management and Technology.

So now you have to decide which career you wish to opt. Take advice from the Career Expert Counsellor and than you can go for the career.

Hope you find the information helpful.
Wish you GOOD LUCK!!!
Feel free to get in touch.
Thank you

Warm Regards,
Prathamesh K.