how can we use the variable
${CDR(disposition)} = status of the call (ANSWERED, BUSY, NO ANSWER)
if i want to use it in GotoIf(???)
to take some decisive action
what should be the arguments

${CDR(disposition)} ,it is the predefined variable automatically set in cdr_custom.conf in asterisk-1.2 or higher

Can you please not post this same question 6 times.

Read wiki about Asterisk Dialplan Variables.