We had multiple tiles boxes contains different quantity of tile pcs. Some boxes contains 5 pcs and some contain 4, etc. How to create conversion of it.
Hello and welcome to the forum,
I see you’re new here so it is ok to ask but it is better to search first
I think if you can search uom topic here then you should be able to find a detailed answer easily. I myself have answered this on this forum.
Documentation have a complete description too please try that also.
After these 2 step still, if you don’t find an answer then come back to this thread 
Good luck.
You can do that in the Item details page by setting the UOM conversation for the Item like the picture below:
and this is the documentation part as well:
https://docs.erpnext.com/docs/user/manual/en/stock/uom
You can create your own UOM (say BOX 5 or BOX 4) and setup the conversion on this UOMs
if we have different items with different number of pcs per box, can we use that mapping with different number of pcs per box for different items?
You can set the conversion factor per item / per UOM, so you can have a multiple choices for each item based on it’s UOM.