What is the eligibility to get admission in St.Thomas College of Education for UG/PG courses?

Indeed, you are most likely to be eligible to do B.Ed course in St. Thomas College of Education (which most probably is the same St. Thomas College you are talking about, there are two other St. Thomas Colleges in Delhi/NCR). The B.Ed qualification normally needs a Bachelors degree (your B.Sc. Nursing) with a minimum of 50 percent aggregate marks. Although teaching methodology might require a certain subject in some of the institutions, a B.Sc. Nursing degree would suffice in getting admission into B.Ed, so you can start pursuing your career in that field after graduation.