Can someone please share a guide on how to maintain a good rank and while starting up late.

its hard to keep a high rank joining late and most people making guides get on a new worlds asap so you might not get one

How late are we talking about joining? Because I started at about tick 300-400, and I am currently ranked #63 and in an alliance ranked #4.

When you start late you should look to join an alliance that looks as though it could go far. Don't try to get in the top 10 alliances because you most likely will get denied unless you know someone in there. Pick a steady alliance and if they are good they will be able to help you.

dont shoot for top 7 alliance i joined tick 2000 in my first world i didn't broadcast that i was a newb and got into 8th alliance

In late starts there is a high chance of you getting conquerd
stick withit tho you can always come out on top my first world was a late start I ended in the rank 7 alliance aslong as your active and play smart you will do fine