kotlin, 168 bytes

Result

AC

Duration

5170ms

Code [DL]

fun main(){var s=readLine()!!
println(s)
val l=s.indexOf('T')
while(0<1)println(Regex("K *").replace(readLine()!!.replaceRange(l,l,"r"),{"r".repeat(it.value.length)}))}

stdin

                    T                             
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                K                                 

stdout

                    T                             
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                    r                              
                rrrrr                              

stderr

OpenJDK 64-Bit Server VM warning: Options -Xverify:none and -noverify were deprecated in JDK 13 and will likely be removed in a future release.
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by com.intellij.openapi.util.JDOMUtil$2 to constructor com.sun.xml.internal.stream.XMLInputFactoryImpl()
WARNING: Please consider reporting this to the maintainers of com.intellij.openapi.util.JDOMUtil$2
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
Exception in thread "main" kotlin.KotlinNullPointerException
	at CodeKt.main(code.kt:4)
	at CodeKt.main(code.kt)

strace