Student or Learner
If I said,
The replacement of this product would be item 2 depending on/depends on where you need it.
Please advise to use "depending on/depends on"
If you are telling someone that something depends on where they need to use it, then you would probably explain to them that the replacement product would be one thing or another.
You will need either Item 2 or Item 3, depending on where you want to use it.
I will dye my hair either red or black, depending on how I feel on the day!
He plans to study either Engineering or History, depending on which course has places available.