awk 'FNR==NR                            ####FNR==NR, FNR and NR are the built in variables in awk, where they represent the number of lines while reading any Input_file, so difference between FNR and NR is, FNR's value will be RESET(whenever we are reading mutiple Input_files) when it starts reading the next file. 
                                        ####On the other hand NR's value will keep on increasing till all the files are read. So in this condition it will be TURE only when 1st file is being read as when second Input_file will be reading then NR's value will be reater than FNR's value as per above explanation.
{S[$4]++;                               ####Creating an array named S whose index is field 4 and by doing ++ to this array so that it could the occurances of that particular index's value, like how many times a same value of a 4th field occured.
next}                                   ####Next, is a built in variable of awk again and it tells awk not to go further and it skips all upcoming statements. We are using it because we don't want to execute all further statements as we need to read Input_file completly 1st time and have the array S's values till the file's completion.
($4 in S)                               ####Now this statement will be executed when 2nd Input_file is being read. Here we are checking like which ever 4th field of line is present in array S. If it is present(which it should be) then following statements will be executed.
{if(S[$4]>1)                            ####Now we are checking here if value(occurance of that 4th field in the Input_file) of array S's whose index is current 4th field of the line being read is greater than 1 or not, if it is greater than 1, it means condition is TRUE then following statements will be executed.
{print $1 OFS $2 OFS $2+S[$4] OFS $5;}  ####Now printing $1, $2 and $3 as value of $2+s[$4](count of 4th field adding to 2nd field, as per your requirements), $5, off course OFS is a built in awk variable which stands for Output field seprator and it's default value is space.
else                                    ####If if condition which we checked above(where array S's whose index is 4th field is NOT greater than 1 then following statements will be executed.
{if($6==1)                              ####Now again here I am checking if 6th's field value is 1 or not, if it is 1 then following statements will be executed otherwise it will go to else.
{print $1 OFS $2 OFS $2 OFS $5}         ####Printing $1, $2, $2, $5's values as per your requirements, again OFS value is space by default here.
else                                    ####It will come to this statement if above if condition was NOT TRUE.
{print $1 OFS $2+$6 OFS $2+$6 OFS $5}}; ####Printing the values of $1, $2+$6(sum of 2nd and 6th field), $2+$6(sum of 2nd and 6th field), $5 as per your requirements.
delete S[$4]}                           ####deleting the value of array S's whose index is 4th field so that duplicate values shouldn't come.
' Input_file  Input_file                ####mentioning Input_files here.