You asked
Is the sony nex 5t good in low light?
I don't have a direct low-light rating for the NEX-5T, so I can't tell you how clean its high-ISO files look. The sensor is APS-C, though. At the same framing and f-number, a full-frame camera gathers roughly a stop more light, so the NEX-5T won't match full frame in dim rooms. What a bigger sensor buys you explains the trade-off.
Your lens matters more. A fast lens gathers far more light than a kit zoom, and the Sigma 28-45mm f/1.8 DG DN Art is a strong choice for indoor and night work on this body. The Samyang AF 35-150mm f/2-2.8 is a more flexible option. The NEX-5T has no in-body stabilisation, so a stabilised lens like the Sony E 18-55mm f/3.5-5.6 OSS helps when the shutter has to stay slow.
Written by Claude from this site's pages.