I am also from India and currently researching similar things because I want to study abroad in the future and possibly go into medicine. From what I have read, an overall band 6 in
IELTS may work for some colleges, but many Canadian institutions and visa applications are safer with at least 6.5 or even 7. I am trying to improve my score because I want to keep more options open later. Right now I am focusing on IELTS for the language requirement, but I am also looking at other exams depending on the pathway. Some students go through
SAT for undergraduate admission, and if someone wants to move toward medicine later there are exams like
UCAT or
MCAT depending on the country and medical school system. A few of my friends even considered
GED before applying abroad. So personally I think if you can retake IELTS and aim for 6.5 or higher it may help reduce risk during the visa process and also when applying to universities.