Your code needs to import java.io.* package. Moreover, it also requires try catch block as it may throw exception. Anyways, we have modified your code. Here its is:

import java.io.*;

class Program { 
    public static void main(String[] args) {
        try{
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); 
        System.out.println("enter a character");
        char ch=(char)br.read();
        System.out.println("the entered character is:"+ch);
        }
        catch(Exception e){}
        }

}