FA/FL or equity instrument

Don't understand your question - you may be trying to over-generalise - every question is a bit different. In scenarios make sure you define equity and financial liability - then apply. Anything on the DEBIT side is always a financial asset.

Sir if there is variability in amount of cash or own equity instruments which will be delivered then such contract is financial liability or equity instrument?

I still am unsure what you are asking. Perhaps you could give an example.