So please let me know which approach should be easier to develop.
it depends of .....
first of all it depends which type of template are you using
for true excel template may be easier one or another based on displaying logic/format and based on logic of retrieving data
i need know which approach i need to follow while writing query.
any from 4
1>Can we write a single query(having multiple subquery) to fetch all data , is it feasible?
why not, did you try it ? if no then try and post feedback