I would *HIGHLY* recommend you seek professional help with this, for several reasons.
First, you've not really provided enough information for anyone to work with here, so my comments may or may not apply to your situation.
For the 2017 tax return, the filing deadline was Apr 15, 2018. For a business tax return such as a 1065 partnership return the filing deadline was Mar 15, 2018. So if you complete the 2017 tax return and a refund is due, that refund will not be paid. The IRS has a 3-year statute of limitations on refunds, so that's why. However, if an extension was filed prior to the original deadline, then you have until Oct 15 2021 to file the 2017 tax return. (Sep 15, 2021 for a business return) and still get any refund if one is due.
Additionally, for a business tax return there is a late filing penalty of $200 per month per partner, for a maximum of 12 months. So that's a potential $2,400 late filing penalty which would probably wipe out any refund due many times over.
Add to that, if you are the legally recognized or legally appointed administrator of the estate, then it's very possible that you personally would be liable for all late fees, fines and penalties. That could really hurt if state taxes are also involved here.
Now I don't know that all (Or any) of the above would apply here. But those are the possibilities and are the primary reason I'm telling you to RUN as fast as you can to a local CPA or tax attorney with this, and get it done yesterday, if not sooner. If possible, the fees for this (probably minus the fines and penalties) can be paid from the estate. But a tax professional will be able to give you the facts as they apply to your specific and explicit situation.
