@kamal.JayapalanThe best way to go about discovering metadata for use with Eikon Data APIs is by using Data Item Browser app in Eikon application or following Formula Builder wizard in Eikon Excel as described in the following tutorial.
https://developers.refinitiv.com/eikon-apis/eikon-data-api/learning?content=14707&type=learning_material_item
The data you're looking for can be derived from income statement / balance sheet / cash flow statement period end date. The following expression retrieves income statement period end date and financial period reference in absolute notation for the last 5 annual fiscal periods for a given stock.
ek.get_data('TREC.K',['TR.ISPeriodEndDate','TR.ISPeriodEndDate.fperiod'], {'Period':'FY0', 'Frq':'FY', 'SDate':'0', 'EDate':'-4'})
I hope this helps.