Can we only get the information about units and precisions or can we modify them using layout peek command.If not is there any other command I can use to set the precision before opening the layout file
Good question. First, layout peek can only view these information but can not edit them. Although there are other tools you can use to retrieve the informaiton from a layout, layout peek is the fastest among these tools because it only scan the file as far as it can get the information, while other tools have to open the entire layout to get just that information.
If you want to change the value of precision of the layout, you can use $L units command to do that when you have the layout open.