Hello Mr. Rajagopal,
According to what you have written I don’t think there is any problem with the programme in the micrcontroller. You said that your 4th 7-segment display is not working well but you fixed it. Now what does that display show when the hours is in single digit? (I mean does is show 0 9 : 5 9 ?) and what does it show after 9 : 5 9?