Hi Mazhar - unfortunately your question is one of those types of question which is extremely difficult for anyone to answer without *all* of the environmental facts, e.g. solution requirements docs, HLD docs, LLD docs, network topology diagram, application solution docs, database design docs, etc.
Plus even if we did have all of those docs, then you're looking at about one to two man weeks of detailed design work, and close contact with solution designers from all areas.
To me, it would seem that someone has already done the scoping and sizing, because you appear to have a loosely defined kit list. Maybe it might be worth going back to the team that generated the kit list to find out how they determined what the kit list should be. i.e. someone must be able to demonstrate why the kit meets the design which meets the requirements which meets the budget.
If someone has picked that kit list out of thin air, then... IMO, you'll be quite lucky to get it to work. It may well work very easily, and you find that you've massively overspent needlessly on too much backup infrastructure.
Riaan's post will help you. The document that Riaan has pointed you towards will not give you a completely worked process for sizing, nor validate your design. The document that you have been pointed towards is meant to help you begin thinking in the right way about what matters in backup planning, and especially about what matters in NetBackup planning.
HTH. Good luck.
