Team.
Is there a way or a query we can use through REST API to get all the information of installed software on computers?
RestAPI is not necessary for this; you can go to the BigFix.me link below, Create an RP (retrieved property) based on it. Once completed, use it to generate a web report and schedule it as needed.
Some more context would really be helpful here. Do you have BigFix Inventory? If so, Inventory has it’s own REST API which can be used to return installed software, yes.
It’s also possible to return information about installed software with the BigFix Platform and it’s REST API as well. As suggested above, do you already have a property or analysis returning this data in the Console or WebUI? Which OS platforms are of interest?