Will the EMI amount or the tenure of the Home loan be affected if the value of the underlying house property decreases

A change in the value of the underlying property does not affect your home EMI payments. Simply because the EMIs you pay are based on the amount of the home loan taken by you for buying the property at a particular point of time. But when there are interest rate fluctuations your EMI might get affected as banks might increase or decrease either the tenure of your loan or EMI payment based on different interest rate calculations.