Yes sir you are right that this was the mistake by me but in future i will remember .

But my code is that :

#include<reg51.h>
#include "uart.h"

unsigned int xdata buff[BUFF_SIZE] = {'P','R','I','Y','A','N','K','A'};


main()
{

unsigned char i = 0;

for(i=0 ; i<20 ; i++)
UART_putchar(buff[i]);

SBUF = ' ';
while(TI!=TRUE);
TI =FALSE;

while(1)
{

}

}

//sends character on UART
unsigned char UART_putchar(unsigned char c)
{
SBUF = c;
while(TI!=TRUE);
TI =FALSE;
return c;
}

This is the program which is working properly means its output :
PRIYANKA

But using char datatype its output is different:

RRYYNNAA

And it takes lot of space using int datatype, and how do i know that those ram i am using that this chip is perfect and this is not faulty.. and i also check my hardware connection that these all are connected in right connection..

Priyanka