Here are some of the things which you should start of with.
1.Get a grip on their Bank accounts ( they should be having only one or perhaps 2 at most)......you can then reasonably construct their P&L accounts,Balance sheet easily which is starting point for you.
2.Download all their Bank statements in a excel file,then you can segment the sources of receipt ( donation+interest income),expenses ( cash,salaries,rentals,other admin expenses etc etc) and other Payouts..
3.On their expenses figure out pattern how much is regular expenses paid by cheque & how much is cash withdrawn for the whole year.From cash withdrawn find out how much cash is available with them now as in physical.
4.Introduce rules ( depends on your influence there & help of their manager/director) to reduce cash outflows & route almost all to cheque payments.Then document their commitments for expenses or services by asking for a business plan focussin on key major spenders of their NGO company.
Rest all should be easy for you,don't raise your expectation to their director saying i will do everything quickly.Hope this helps.
Usually the people who commit money for NGOs ( as in govt,charity,companies) will demand outcome for the money they spend & raising money for NGOs is dependent on how good their financial record is also in terms of basic housekeeping & quality of information you share with your donors.Hope this helps.