How i can make this child box in middle of main box without using position property?



Hello @Amaragarwal7 ,
Thank you for placing your query.

lets use some proper notation,
sky-blue box is referred as child and dark-blue as parent div

If you want get the desired o/p then
set large quantity of padding to parent div and also set width & height to parent div as fit-content & background-color to blue

And regarding child div set a width , height with some value and also give margin as auto to child div.

So now you can achieve the o/p mention in Image.

once you are done with complete reading of this post, for better outcomes please try once by your own end.
and later you can check for this reference link

Ganesh Patil | TA - Edyoda