MBA/PGDM

No, it will not affect at all as you are going to have a job experience during that time.

Hello Aksa,
It will be difficult without work experience as business schools prefer applicants with a minimum of 2-years of work experience for the MBA programmes. You can look out for PG Diploma programmes, very popular here and also you can check out the MS Management courses.

Dear Dipangshu,
There are striking differences between the two programs. The answer will depend on which course you prefer and your career plans. Typically MBA is for people with work experience, the MBA class is full of managers, senior managers, VPs, etc. MS Management is designed for fresh graduates. You can figure it out now.

It will be purely based on your CAT-score (or other entrances' score). You have not mentioned which region you are looking for. Check out this link for your choices.
http://www.time4education.com/CAT-MBA/About-MBA/TIME-B-School-Categorisation
Hope this will help.

IGNOU is better according to me.

MBA does not need you to be good at theoretical knowledge. It is more about practical experiences that you gain during your course of 2 years. It is the applications of your theory. So, MBA in HR or any other field like Marketing, Finance or Operations will not need you to be good in theory.

Never think negative or doubt your own abilities. 60% marks is the minimum criteria for admission in any good college, and if you want to pursue your career with decent earning, then you must put in some efforts for it. To gain those marks, you will have to prepare a timetable and study accordingly. Also, keep some time for your recreational purpose, as it is needed for your holistic growth. Last but not the least, be sincere towards your studies and study well in order to get admitted in a reputed college and start a great career. Remember; Admission in a good college is were half of your career is made.