Hi there, which one is more correct in the following context: 'it' or 'this' ?
1- John‚ have you heard that the government has decided to cut fifty four thousand trees for a new project? Is it/this right? What do you think?
The sentence will be ambiguous no matter which one you choose. It's unclear whether the sentence is supposed to mean "Is that correct?" -- i.e., "Is the information I have given you correct?" -- or "Is this an ethically condonable course of action?"
I presume it is supposed to have the latter meaning, because (assuming "What do you think?" belongs to the example and is not your/Subhajit's question to us) the speaker is asking for the listener's opinion. I recommend changing the question so that both "it" and "this" are used:
1a-John‚ have you heard that the government has decided to cut down fifty-four thousand trees for a new project? Is it right for them to do this? What do you think?
Please note that there is a hyphen in "fifty-four thousand." I have also added "down" after "cut" for additional clarity.