Can i take indomethacin 4 hours after an oxycodone/apap?

Yes: There is no problem with doing this.

Alternate drug thera: If you have been prescribed both the oxycodone/acetaminophen and the indomerhacin, I would say a resounding "yes!" It is a good idea to alternate a non-steroidal anti-inflammatory medication with a narcotic. You therefore minimize your narcotic intake. The sooner you can rely only on the NSAID, the better! Good for you!