To find and unlock the safe in the “Blood Feud” mission of Call of Duty: Black Ops 6, follow these detailed steps:

### Step-by-Step Guide to Unlocking the Blood Feud Safe

1. **Locate the Restaurant:**
– After meeting with Sevati in the white van and sniping Yannik, proceed to the restaurant on the first floor.
– If you enter through the front door, the stairs will be towards the back left. Instead, head to the left of the stairs to find a doorway leading to the safe room.

2. **Enter the Office:**
– Enter the door to arrive at an office where the safe and a radio are located.
– The radio will be to your immediate left.

3. **Locate the Radio:**
– Interact with the radio to tune the frequency and amplitude.
– The left side of the radio controls the amplitude, and the right side controls the frequency.

4. **Adjust the Waveforms:**
– Turn each dial until the lights on either turn green.
– This will initiate a broadcast that repeats the safe code, which may vary for different players.

5. **Unlock the Safe:**
– Enter the code that is broadcasted by the radio into the safe.
– The safe will unlock, and you will receive a reward of $1000.

### Alternative Routes

If you prefer a more stealthy approach, you can use the vents:

1. **Find the Vent:**
– Look for a white van parked in an alleyway near the restaurant.
– Climb the cardboard boxes behind the van to reach a ledge where you can open a vent into the building.

2. **Navigate Through Vents:**
– Enter the vent and take the first right, where you will hear two guards talking.
– Remove the vent panel to kill these two enemies and then drop down into the room.

3. **Proceed to the Safe Room:**
– Move through the room, avoiding or taking out any enemies you encounter.
– The safe room will be to your right or left, depending on which vent you dropped from.

4. **Unlock the Safe:**
– Follow the same steps as above to unlock the safe using the radio in the safe room.

### Summary

– **Location:** The safe is located in an office within the restaurant.
– **Method:** Use the radio to adjust the frequency and amplitude until the lights turn green, then enter the code to unlock the safe.
– **Reward:** $1000.

By following these steps, you should be able to unlock the Blood Feud safe in Call of Duty: Black Ops 6 and claim your reward.