DTU - Delhi Technological University

The admission cutoff for DTU varies every year depending on various factors such as the number of applicants, the difficulty level of the exam, and the number of available seats. It is difficult to predict whether you will get admission to DTU with 77 percentile as the cutoff varies every year. However, based on previous year cutoff trends, it is unlikely that you will be able to get admission to DTU with 77 percentile in the general EWS and Delhi quota category. But there are many other good colleges and universities where you can apply with your JEE Main score, such as:
Indraprastha Institute of Information Technology (IIIT) Delhi
Netaji Subhas University of Technology (NSUT)
Delhi Technological University (DTU)
Jamia Millia Islamia (JMI)
Guru Gobind Singh Indraprastha University (GGSIPU)
Amity School of Engineering and Technology
You can research these colleges and their admission cutoffs for your category to determine your chances of admission.

The mathematics that a more experienced programmer WILL NEED in the workplace is covered in computer Science courses. The mathematics that a computer scientist WILL require and a programmer MIGHT need are included in the subject of mathematics and computing. You mention that you want to work in the software development industry, therefore computer Science would be the best option for you (in my opinion), since I am a firm believer that you can learn what you need as and when it is needed (something you will already have to do). It is a waste of time (again in my opinion) to devote some of your college time to academics to studying something you might need. However, a very small percentage of people choose Maths and computing.

Your interest will determine this. Software engineering should be your first choice if you're interested in coding careers; but, if you're genuinely interested in mathematical coding, algorithms, and statistical analysis, mathematics and computer should be your first choice. Each branch has its own set of benefits and drawbacks. The Department of Computer Engineering is responsible for software engineering. The main focus of your four-year study schedule is software development. The curriculum has been upgraded and is regarded as superior than computer engineering. The DTU Department of Applied Mathematics is where mathematics and computing are housed. The course content is arranged so that students learn the necessary coding abilities as well as all the significant mathematical components of scientific inquiries. The course is quite challenging, and you'll be haunted by pure mathematics.