Yes.
You can recover the data you lost.
All you needed is the suspected time of the data lost. Provide the schema name of the project, from where the data has lost. ask them to get the back up of the earlier day (Depends upon the backup infrastructure made in your environment).
Note:
1. Back up must be in incremental leval (Schema level) not the entire environment.
2. No down time required in backing up the process, should go for RMAN Hot back up.
Get in touch with your DBA for more details to retrieve the same.
Try these activities in your Test ENV before you perform directly on the PROD.
