Indian Railways — nuisance of people without reservation over reserved ones

People jump into reserved comportments and starts an argument over a seat which is already reserved.. Today a senior citizen got in the train putting hankie for his seat and did the same on my seat... When told by the passenger beside me that the person is coming.. He yelled like if the that person doesn't come then see what I do.. As he refused him to sit as it was reserved for me.. I hope u do the needful... Thank you