can the presnt perfect continuous tense is equal to future perfect tense? why?
Both the tenses mentioned by you are different.
Present Perfect Continuous Tense is used for an action which began at some time in the past and is still continuing.
Future Perfect Tense, on the other hand, is used to talk about actions that will be completed by a certain future time.
Examples of both would clear your doubt further.
Present Perfect Continuous Tense:
He has been meditating for three hours now.
They have been working on this project since last 18 months.
Future Perfect Tense:
By the end of this month, I will have studied in this school for 7 years.
Her brother will have left before you go to see him.