If you score around 51 marks in the COMEDK exam, your rank will depend on the overall difficulty level of the exam that year and how other candidates performed. Generally, with 51 marks, you might get a rank somewhere in the mid to lower range since the exam is competitive and marking is relative. This score may not be enough for top-tier colleges but could  give you a chance at some private, depending on the total number of candidates and cutoff trends that year. keep an eye on official counselling updates and previous years’ trends.