my Q:
before any body want to learn microtik what it need to study or read to under stand every thing in microtik
Without knowing what you already understand it’s hard to say. Just for starters.
At least basic networking and routing. How IP, ICMP, UDP, TCP, … work together. What host addresses, net masks, network and broadcast addresses are.
How to setup the networking on a Unix/Linux box,
How basic services like DNS, DHCP, NTP, … work and how to set them up on a Unix/Linux box.
How to configure any router or firewall would be a big help. If you’ve configured Cisco routers before you’ll find that very helpful.
If you tell us what you already know we could be more specific.