Dear Raju,
It certainly depends on company's leave policy. If it is mentioned in the leave policy that any leave taken along with weekly off coming after or before week off will be treated as leave then you have to consider it as leave vis a versa.
Example: If a person's week off is Thursday and he takes leave on Wednesday, resumes duty on Friday then only Wednesday will be treated as leave and Thursday as week off. If he fails to come on Friday then you can treat Thursday as leave.
Regards,