I saw your file,
What I meant by rendering engine was if you're using V-Ray or Arnold etc,... to render your scene.
You have some issues with your files, I'm going to mention some of them:
1- From the Display panel I unchecked Lights and I saw lots of lights in the scene!

And this is Bad! it will make your rendering longer and create some artifacts, etc,...
I deleted them
2- You have lots of light around your project that are not necessary

I deleted those V-Ray lights, in addition to some omni lights at the entrance,
And I added a V-Ray Dome light for the environment lighting
And 3 Rectangular V-Ray lights at the front the 3 entrances.
Adding Vray Lights
3- I adjusted the Mapping of the fabric in the ceiling.
I suggest you use V-Ray materials and not Standard, I didn't change it, but I suggest you do,
It's a bit faster.
4- In your original scene, there were lots of color bleeding from the Red objects on the surrounding
Objects. It's because of the amount of red and high saturation.
Color Bleed
So I decreased the Saturation value in the GI tab to 0.5
Decrease The Saturation
For the Noise, in the Irradiance map rollout, I set it to High with a Subdvs of 50,
And I've set the Light Cache Subdvs to 1500
Irradiance map and Light Cache
Also, in the Vray tab, you can check the settings below
Image Sampler...
Remember that I didn't change all, and there is a lot to say about the scene setup,
In the matter of lighting and materials,
I also suggest you check some tutorials on how to work in Gamma 2.2 workflow since it produces
Better results in less rendering time
This is the render after the few adjustments I made:

You can continue adjusting the scene as you like, maybe adding or deleting lights to
Emphasize some areas, etc,...
This is the Max scene after the few adjustments:
https://drive.google.com/file/d/1ZFZcA7gcXqQ6jBDoGHUrleVgstfDs-_1/view?usp=sharing
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[email protected]3DS Max 2025, V-Ray 7
3DS Max user since 2003 (3DS Max 7)
V-Ray user since 2008 (V-Ray 1.47)