HYDERABAD: A 19-year-old student allegedly stabbed his father to death after losing Rs 6 lakh — a loan the victim had secured after mortgaging his property for the son’s engineering coaching — in online betting and then tried to cover his tracks by claiming that his father died by suicide due to financial distress in Hyderabad Gopanpally suburb on Tuesday.Police arrested the accused, Kethavath Ravinder, for killing his father, Hanumanthu, a 37-year-old mason, on Wednesday.The victim’s younger brother and auto driver, Kethavath Ramesh, said that Ravinder had called him around 2.30 pm on Tuesday, claiming that his father had died by suicide due to financial distress. The family believed Ravinder’s word and even began funeral…