Hello @kartik,
I think you can use the "engines" field:
{ "engines" : { "node" : ">=0.12" } }
As you're saying your code definitely won't work with any lower versions, you probably want the "engineStrict" flag too:
{ "engineStrict" : true }
engineStrict is now deprecated, so this will only give a warning. It's now down to the user to run npm config set engine-strict true if they want this.
Hope this is helpfull!!
ThanK you!!