A small tick can just be part of the normal noise an ICE engine makes.
Some things to consider: Is the oil level correct? Is the oil "fresh"? Engines always get noisier as the oil accumulates miles. At 5K miles it is amazing how much quieter an engine gets with fresh oil and yes with the fresh oil at operating temperature, too.
Is the oil the right type of oil? Synthetic if required, and of the proper (multi-viscosity) grade? Because I take it the car is used but new to you you probably have no idea of how many miles are on the oil and what oil the previous owner used.
Since I can't hear the tick -- this is not a hint to post a video/audio clip -- and can't judge for myself how bad or not it is you might consider having this tick checked out by a qualified tech to get a professional's opinion.
I suspect that you are experiencing the famous "Hemi Tick" as you've titled the thread. I have a 6.4 with less than 9000 miles, and I was also concerned about the rapid tick, tick, tick. From inside the car, it originates near the dash board and glove box. From under the hood, it's near the rear of the engine. I suspect this is just the personality of this engine, hence the name "Hemi Tick." Dealership listened to it, and agreed - normal.
Double check all fluids, belts, look underneath, etc. for anything unusual, correct levels, etc. Shine a light in the oil fill, etc. just to be sure.
I'm not an engineer but constantly learning on this stuff. Many believe the "hemi tick" can be mitigated by better lubricants, e.g. oil and gasoline choices. First, gasoline. I'd suggest only non-ethanol premium gas. My understanding is that ethanol gas may rob lubricating properties from the engine.
MUCH discussion on the correct oils. I've learned a lot here and elsewhere. Here's my theory. These Hemis were filled with XYZ brand of oil from ~2008 until ~2015. There seems to be a small but vocal history of problems with premature wear on cams and lifters. The Mobile 1 that was filled in these originally, has a very low MOLY content if you look at virgin oil analysis. Here's a VOA I've taken off another website. Note, Mobile 1 is no longer the recommended oil.
Compare that with the Pennzoil Ultra Platinum 0w40 that developed a SRT formula for our Hemis. I also grabbed this from another site. Notice the differences, especially the moly. The PUP has a lot more moly (but less phosphorous and zinc, the anti-wear additives). I don't know if this will make a difference but the PUP is the recommended oil now. Maybe a gimmick, maybe legit additive package developed after ~6+ years of reported upper lubrication issues, especially cams and lifters, rocker assemblies, etc. I'm about to drain the Mobile 1 in my Hemi and replace it with the PUP and see if there's an audible difference. It's a $70 experiment (and less than a mechanic's time) to see if I can improve the lubrication in my engine, so it's happening for me, soon. If you search around there's a really good discussion on the Hemi Tick causes and remedies.