Hello Vrukshat. As you have mentioned you want to get into University of Mumbai for pursuing BCom. Mumbai University is a very reputed college. Every year the number of candidates applying for Mumbai University are more than 5 lakh. Among so many candidates your profile needs to be extraordinary in order to get admission there. Mumbai University releases 3 merit lists every year. After you have submitted the admission form for the college, they release the merit list. Mumbai University in particular releases its first merit list on 13th june. The second merit list will be released on 17th june and the third one on 20th june 2019. 

The KC college of Mumbai is rewarded as one of the best colleges of Mumbai. This college also releases three merit lists. To get admission in this college also you need to fill the online form first and then after the release of merit lists you can get admission according to your score. 

All colleges have an application form to be filled first which you can find on the college's website. I hope I was helpful to you. For any further queries, feel free to ask. Thank you