Kindly change your boarding point from chittor to tirupati at nearest PRS Center to be on safer side. Though TTE usually waits for next halt for passengers to board but its not a rule. Go to PRS Center 24 hrs before departure of the train from source along with photocopy of your e-ticket,id proof and an written application requesting a change in boarding point. please note that there will be no change in your seat,nor the qouta will change.