Hi @soumyodeep and welcome to Grey Arrows 
You may have misunderstood their rhetoric. Which is understandable as it is very much designed to be misleading.
Land owners cannot prevent you flying over their land. They will very much try and convince you they can, but they can’t.
They can prevent you taking off and landing, but there are plenty of public places you can TOAL from, then enjoy your flight over NT, EH, etc land 
And on to the formal welcome 
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Welcome once again!