If i am trying to instantiate cells from magic device1 bar , for the vias and mcon , its complaining below : Also i dont see any tab opening for options. ia1 width must be at least 0.26um Via2 width must be at least 0.28um Mcon width must be at least 0.17um

These are not parameterized cells, but just simple helper functions. You need to set a cursor box around the area where you want the via and then select the via from the menu. I'm open to changing the method to do something different or more useful; e.g., create a cell containing the contact, or create a minimum-size contact centered on the cursor box if the cursor box is smaller than a minimum-size contact.

"create a cell containing the contact, or create a minimum-size contact centered on the cursor" -- what you mentioned i think will be really good to have. May be create from the origin of the box a minimum sized via cells OR/AND array of vias which could be specified by options (helpful for VDD/VSS connections)

The way magic represents vias makes the array unnecessary. Magic's via is really just a rectangle into which via cuts are placed in an array when magic writes out GDS. So you can think of magic's drawn via layer like a LEF "viarule generate" block. So if you want a via array, you just draw a larger rectangle.

… which is quite nice once you get used to it. I always found the “other” way of figuring out how much of an array will fit and then play with the parameters in a dialog a bit cumbersome. The downside is you never know how many vias you will get, so calculating max. current of the vias is not straightforward.

You can always select the via area and do, e.g.

cif see VIA1

and count the number of cuts.

Yes, that would be helpful, but please also keep the “old” way of just filling the box with the proper via selected from the dropdown. I found that quite handy.

Always good to get feedback about how people are using the tool.