For a Career in Astronomy you should ideally Graduate in Physics followed by PG in Astronomy, Astrophysics or Radioastronomy from reputed institutes like IIST Trivandrum, IISc Bangalore as well as Top IITs. Careers in India are limited to Government Labs, Observatories as well as Research Organizations like ISRO, IISc and Radio Astronomy Centres, though the private Space Research Sector is steadily growing in India. You may aspire for a PhD abroad in US, UK or France for better career scope and prospects.