Launched in the year 2022, the 75C635 is a 75" 4K TV from TCL. It features a 10-bit VA panel.
The maximum resolution it can display is 3840 x 2160 with a refresh rate of 60 Hz and a pixel density of 59 ppi.
Picture Quality
After screen size and resolution, the next important feature to look for in a display is its Color Reproduction, which is defined by its color gamut specification.
TCL has not provided a color gamut rating for this TV. But don't worry, we have other means to guess that.
Now, since the TV features amassive 75 inch screen, it won't come with a cheap panel, so here we can assume its equivalent sRGB coverage to be 90-100% or above. The color accuracy on this TV should be Lifelike! Meaning it is capable of producing color accurate images by default.
What is Color gamut ?
Color gamut spec of a TV indicates the range of colors that the TV can display.
A TV with poor color reproduction will produce undersaturated/washed out colors that will not be pretty to look at.
Different manufacturers use different measurement standards to define color gamut. Such as — sRGB (most popular), NTSC, DCI P3 etc.
But you don't need to worry about that, here is a chart that will help you choosing a TV with good color accuracy.
Now, next in the list is Static Contrast.
Why its important?
A TV with low static contrast ratio will not produce deep enough blacks and possibly can bleed backlight as below:

The static contrast ratio of above TV is 800:1. So make sure you get a TV with a static contrast of >= 1000:1. More is better.
Also, a TV with high constrast ratio allows you to see more details. So, resolution and static contrast ratio go hand in hand in a sense.
If given a choice, I will prefer a FHD TV with high contrast ratio over a 4K TV with low contrast ratio.
This TV is rated with a static contrast ratio of 6000 : 1., well enough to achieve deep blacks. The panel comes with local dimming which is a plus.
HDR10, HDR10+, Dolby Vision and HLG (Hybrid Log Gamma) are also supported on this TV, so that's a plus.
Coming to brightness, it can go as bright as 250 nits. The backlight used on the panel is Direct LED.
Gaming Performance
If you are planning to use your TV solely for content consumption, you can ignore these specs. But if you are also planning to use the TV for gaming or use it as a PC monitor, you would want to get a TV that features the lowest input lag and response time.
Sadly, TCL did not specify the input lag on this unit. Now, since this is not a cheap TV from TCL, we can expect an input lag of less than 20ms.
Understanding Input lag and response time
This lag is the latency at which your device inputs changes the content of the TV. Though, this won't matter much if you aren't into competitive/FPS games like call of duty.
Although for better experience, look for a TV that has an input lag and response time of less than 20ms.
Dimensions and Ergonomics
Vertically, the TV measures 75 inches and horizontally 65.79 inches.
It is 3.9 inches thick.
It weighs approximately 29.0 KGs, another 0.5 kgs including stand. So plan your space accordingly.
Now, speaking of ergonomics — VESA mount is supported on this TV with an interface size of 400 x 300 mm. The unit doesn't come with either Swivel, Tilt or Pivot support.
Hardware and Audio
The TV comes with a 1.3 Ghz Quad Core (ARM Cortex-A55) CPU along with a 2-Core 0.8 Ghz (ARM Mali-G31) GPU.. There is no mention on the total RAM on this TV.
For display connectivity, TCL has provided two HDMI 2.0 ports, one AV Composite In 3.5 mm jack port and one HDMI 2.1 (4:2:2) port on this TV.
For connecting USB devices, it includes 1x USB 2.0 and 1x USB 3.0. Other connectivity ports include — 1x CI+ 1.4, 1x Satellite In (F-type female), 1x Antenna (RF) (female) and 1x Ethernet RJ45.
Regarding wireless connections, the manufacturer has provided Wi-Fi (5Ghz + 2.5Ghz), Wifi-Direct, Bluetooth 5.0 and DLNA.
The Audio unit of this TV is powered by 2 x 15W speakers.
In terms of power consumption, it consumes 172 Watts on average and 0.79 Watts on standby.
Both 110V and 220V outlets are supported on this unit.