Hi Sweta,
from what you describe I would use the Interest rate instrument (the Product category 550) and then assign an appropriate Position management procedure of category 'Securities/ Loans/ Money Market/ Listed Options Normal style (without index-linked bonds)', consisting of at least Amortization and FX valuation steps - as certain flexibility is available in all these elements, please test if these settings give you expected results and adjust if required.
hope this will help you.
Kind regards,
Renatas