Index/Match combined with Count

You will usually find that you'll get an answer more quickly if you attach a sample sheet. However, I had a file "in stock" that matches my "best guess" for what you want.

If there can ONLY be one maximum number per state, copied down:

=IFERROR(INDEX($B$1:$B$48,MODE.SNGL(IF($A$1:$A$48=E2,MATCH($B$1:$B$48,$B$1:$B$48,0)))),"")

If there can be several, this formula identifies how many tied results there are, copied down:

=IFERROR(SUM(--(MODE.MULT(IF($A$1:$A$48=E2,MATCH($B$1:$B$48,$B$1:$B$48,0)))>0)),"")

and this one, copied across and down identifies the tied values:

=IFERROR(IF($G2>=COLUMNS($H:H),INDEX($B$1:$B$48,INDEX(MODE.MULT(IF($A$1:$A$48=$E2,MATCH($B$1:$B$48,$B$1:$B$48,0))),COLUMNS($H:H))),""),"")

these are ALL array formulae.
Array Formulae are a little different from ordinary formulae in that they MUST be confirmed by pressing CTRL+SHIFT+ENTER to activate the array, not just ENTER.

You will know the array is active when you see curly brackets { } - or "curly braces" for those of you in the USA, or "flower brackets" for those of you in India - appear around the outside of your formula. If you do not use CTRL+SHIFT+ENTER you will (almost always) get an error message or an incorrect answer. Press F2 on that cell and try again.

Don't type the curly brackets yourself - it won't work...

Another option to consider:

You could also achieve this using a Pivot Table, Slicers and cell reference.

If you make the source data into an Excel Table, it will be dynamic in range - ideal for a Pivot Table.
By setting the PT to show only the Top-X, where "X" = 1, it will always display the company with greatest count.
You only need to reference the cell containing the company and count.

PT do need to be refreshed when data are changed and this is easily automated with VBA.