Formal:
* Awaiting
* Under consideration
* In progress
* Unresolved
* In suspense
* In the balance
* In the pipeline
* Subject to approval
* Contingent upon
Informal:
* On hold
* Up in the air
* In limbo
* Waiting to be seen
* To be determined
Specific to legal contexts:
* In litigation
* Before the court
* Sub judice
Other:
* Unfinished
* Incomplete
* Undecided
* Uncertain
* Unsettled
The best synonym to use will depend on the specific context of your sentence.