Raising new issues after written statements stage in civil case

I am hindu, from Tamil nadu. I have filed civil case for partition of my late father's cooperative bank deposits, in which nominee for my late father's deposits is my younger brother. I have asked for one fifth share of my late father's deposits. Mother is no more. There are 6 defendants. D1 & D2 are GM & Secretary of Co-operative Bank, d3 to d6 are my siblings. D2 & D6 filed written statements towards my partition suit, with d2 putting onus of proof of deposits on me, while d6 rejected my claim in their written statements. At this stage, I have found that co-operative Bank may have misappropriated my father's bank deposits. If Nominee is unwilling to raise this issue, kindly let me know how I can ask for statement of accounts from Bank D1 & D2.