If you can post screenshots of it you should be able to post the manual. The short excerpts doesn't show enough information.
I have a Reader manual with command address but i dont know the arduino library which is suitable?
From the information you provided the only library I can identify is HardwareSerial, but that one is an integral part of the IDE, you simply access it by the "Serial" object.
i want to communicate arduino uno board with UHFReader using RS-232 without modbus address?
How did you get to ModBus in this regard? The manual doesn't mention ModBus in any way.
We now have seen the manual. What exactly do you want to achieve with that?
Remember that an Arduino UNO only has one hardware serial interface. This interface must be used to communicate with that UHF reader (the baud rate of 57600 is much to high to allow for a software emulation), so you cannot use the USB connection to the PC at the same time. If you want to display some values you either have to connect a display to the Arduino or change to another model which has additional serial interfaces (p.e. Leonardo, Mega2560, etc.).
it means cannot communicate using RS-232 over MODBUS ??
No, it means that device doesn't know anything about ModBus, but this also means you cannot use a ModBus library to communicate with this device but you have to write your own or put everything into the sketch.