Look at the sticker on the PSU. All the details would be there. At least mention the model number and we will try to say if its good or not.
I checked the sticker. It says 385 watt (max 400 watt). But the problem is, my PSU is not from a brand. It was with the casing. One of my friends said that I shouldn't always trust the sticker unless they are branded. I know some cases where it is actually true. That is why I asked that question.
The wattage in modern times is a bit low. But that depends on the type of rig you have. If it came with the cabinet, then i suggest you discard that PSU and get a fresh new one from a reputed brand. Brand matters a lot when it comes to PSU's.