Import payment direct remittance

Dear sir,

We are importing materials & machinary from my parent company from April 2011 to till date.  Credit period mentioned in this invoice itself 85 days from the date of invoice, but we have not settled single paise to them ( because they told me, take your own time and settle)

Is there any instruction from RBI, need to settle this payment with in time, if available please tell me the time frame.

atleast we can start from now onwards.

thanks