I have scored 53.8% in HSC exam. Recently, I am doing BBA. Am I eligible to do MBA in another country?

Yes, you can do MBA in UK. You need minimum 50% marks in your BBA also. You may need to do IELTS to prove your English proficiency.

Yes, you can do it, provided you clear GMAT test. A decent score of 650+ will get you good colleges.

Yes, you can do MBA.

Yes, you will be able to do MBA in Europe but some colleges require IELTS score and 2 years work experience.

Yes, you can pursue MBA overseas post completion of your graduation. You need to decide this keeping in mind your interest areas and long term career options & other related conditions.