During nursery admission interaction not drawing but coloring is an integral part. In some schools during the nursery interaction kids are given coloring worksheets and colors to fill in. This is done to check both the coloring skills of the child and also to see color recognition ability.
For example school will give worksheet with a apple drawn on it and child will be asked to color it. They will check whether child colors the apple red or not and also how well the child fills the color in the apple and so on.
Very simple images are usually given so parents just need to teach kids about basic and and few objects of the respective colors like sun, apple, flowers, clouds, trees, moon, carrot, mango etc. Yellow, green, blue, pink,red white are the few colors kids should be able to recognize.
If your child can do little more than this i mean according to his or her capability start teaching some drawing basics. Drawing and coloring are generally something that kids enjoy doing specially colors. Now to begin with drawing give your child at least one dot to dot drawing each day or randomly give any shape or just lines which they have to outline. Daily one is not really too much. This will really help your kids learn drawing basics. If your child scribbles never stop him from doing so as this is one very important part and helps a lot in practicing art. When they scribble their hands become flexible...just stop them if they are tired as the bones at this age are not very strong.
If your child knows how to write alphabets like A B or C then alphabet drawing also helps them learn drawing really well. Actually alphabets are not asked during the nursery interaction as this comes in the nursery syllabus but if your child is already in nursery or KG then alphabet drawings will really help.