Admission to IMI Delhi 2020 will be offered on the basis of candidates score in CAT, class 10th and 12th, relevant work experience and personal interview. You have 10, 12 and graduation marks in 60s as you said, which gives a negative impact though you have an advantage of having three years of work experience.

Last year, IMI Delhi had CAT cutoff of 90 percentile and sectional cutoffs were-

VARC  -  75

DI & LR  -  70

QA  -  70

You know the cutoffs change every year as it depends on various factors. Try to score more than 90 percentile so that all the negative sides can be covered up.

https://bschool.careers360.com/articles/imi-delhi-cutoff

All the best.