What video file format are you currently exporting to? And, at what settings?
Using premiere CC
my output 3840x2160, with square pixels, lvl 5.0 with main profile and main tier
The sequence is a 3840x2160 (1.0) same as output, but some one it drops the quality when rendering
Can we please see a screenshot of your render and output settings?
Either of the following two options will give you great image quality:
A. Add your Comp to the Adobe Media Encoder Queue. Then, set the format to HEVC (H265) and the preset to Match Source - High Bitrate.
B. Add your Comp to the Render Queue. Then, set the Render Settings to "Best Settings" and the Output Module to "Lossless". Heads up: You're looking at 32MB per frame (a lot more if you're working at higher than 8 bits per channel).
Another consideration is how you're going about playing your rendered movies to your TV. If your TV support playing H265, you're all set. You're also probably good if you're playing H265 files to your TV via HMDI from your laptop. If your hardware requires something else, you'll have to consider working with whatever it supports.
Are you still facing this problem? If not, let us know how you solved it. If so, please let us know so we can assist you further.