Medical negligence

In the last week of Dec 2022, my father underwent an amputation surgery of a finger of his foot, on the advice of a medical specialist in a reputed private hospital in Bengaluru, Karnataka. My father was a diabetic for decades and with cardiac disease, all of which were made known to the specialist, before the surgery. Immediately after the surgery, my father began to show breathlessness on rising up from bed or chair. This symptom, I learnt from medical literature, indicates damage to the heart. Two days later, my father was discharged and again examined after two days by the specialist, for re dressing the wound. Even on bringing the critical breathlessness symptom to the specialist's attention, he did not attend to it but referred me to other physicians. Two days later, my father suffered a heart attack at home and expired. I then perused many medical literature sources and learnt that the surgery carried a very high risk of mortality that I was never made aware of during consent. This case thus amounts to serious medical negligence. Should I seek compensation from a consumer forum or should I file a petition with the High court of Karnataka?