HEllo Dear,

for space and time, one course called, astronomy. you first need to complete your graduation in Physical Science, which includes 5-year integrated courses (BSc + MSc) or 4-year BS programmes or Engineering (physical sciences), or 3-year graduation degree (BSc) followed by MSc and then later you could do your PhD.

https://career.webindia123.com/career/institutes/list_colleges_Institutes.asp?group=129

good luck