Does your use of the word "congestion" really mean concatenate?
If so you can not concatenate two chars into one, you have to put them next to each other in an array.
char x = 1 ;
char ='g';
i need to show 1g
x is not a char that will ever be displayed as 1, it is char = 0x31 that will display as one.
As AWOL says you need to say what it is you are trying to do because what you are asking does not make sense.