Hello Aspirant,

Its possible to get into astrophysics with an engineering degree.

Following aspects can be taken in mind:

1. Qualify GATE with good percentile and join Integrated PhD (i.e MSc/MTech + PhD) at various(10+) research institutes in India for example, IUCAA, IIA, NCRA, TIFR, IISc, IISER’s, etc. You will find many engineering graduates pursuing their PhD in these institutes. I will provide you essential links at the bottom of the answer.
2. Some of the research institutes also conduct their own personal entrance exams for Integrated PhD/PhD in that particular institute. You can find those by visiting institute website. For example, IISER’s conduct their own entrance for Integrated PhD/PhD. So, you can either qualify GATE or IISER’s exam to get into PhD in IISER.

All the best!