perl6, 91 bytes

Result

AC

Duration

1339ms

Code [DL]

my $s=get;$s.say;my $k=.index('K'),say $k??.subst('K','R'x$s.index("T")-$k+1)!!$s for lines

stdin

                  T                               
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
       K                                          

stdout

                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
                  T                               
       RRRRRRRRRRRR                                          

stderr

strace