Hey Mate

hope you are doing well, So i will answer you for this question from starting

first you have to go for an MBBS for which

you can go for NEET,AIIMS or any other entrance exam you can even do MBBS from foreign after which you have to clear exam called FMGE

after that you have to go for MS specialization in cardiology

for this you have to complete NEET-UG

for more details you can go from these link

https://medicine.careers360.com/exams/neet

https://medicine.careers360.com/exams/fmge

https://medicine.careers360.com/exams/neet-pg