All LED tubelights will come as a single unit. They do not have the twist and turn tube lights from the past anymore. So there is no holder and tube separately.
If you are looking for an affordable, single colour option, the Wipro Garnet ones are decent and will last you sometime (I have some running from 2018).
You can never go wrong with a
Phillips one. I have a few of these Warm White tubelights from them which work well. However, if you are buying in bulk (4/8 units, then Wipro's is slightly more cheaper).
If you want to get a smart tubelight which has a decent colour (White -> Yellow only) and brightness range,
Wipro sells one which is decent. I have 2 of these running since a year now. You should use the Tuya app instead of Wipro's app which is substantially better. (Wipro tubes are basically white labeled Tuya ones).