Yes, you can take admission in engineering courses even you having biology in 12th, it is irrespective of what ever you studied before 12th if you manage to clear entrance exam essential to assure your seat in colleges which runs respective courses for fields like engineering,medical,commerce,etc.

For cyber security kind of jobs , you can give a try for computer engineering , Information Technology , BSc. courses like computer science,etc like courses. But again here competition is very tough. Candidate who understand various know-how of this field can survive the jobs you mentioned.