Hello, hope you are doing well!

You can get into BSc CS in Delhi University and still prepare side by side for the various entrance exams of BTech CS. A lot of people get into any academic course and side by side keep preparing for entrances. So, that there is no chance of year loss even if one can't crack engineering entrance exam the next year. If you crack the entrance next, which I am sure you will definitely do, you can continue with engineering and leave BSc. Just that you need to properly study with full dedication for a year.

In case you don't succeed in cracking your entrance next year, start doing coding courses along with BSc. Don't quit on your passion and interest.

So, get into Delhi University this year itself. It is a renowned university and BSc is also a worthy degree. Once you get into Delhi University, start preparing for Engineering entrance exams that you will attempt next year. This year it won't be much trouble to manage both things at the same time because I guess BSc classes by Delhi University will be given in online mode due to pandemic situations. You don't need to attend classes in physical mode so your travelling time is saved(you can utilize this time for studying for engineering entrances) and also in first year any degree course is comparatively easier than its second and third year syllabus.

But you can't get diverted and you need to be fully dedicated into studies. Nothing is easy and possible if you don't work hard. So, be determined and don't be scared. You will be great!

All the best!