How to condition and reference cells in excel 2012

pls i need some help here. I want to the summation of particular cell be subject to the summation of another.

For example, I have four categories of ranges which must give total of 100. However, I want total summation of category must be btw 65-70. If it is 70 then summation of other must be zero.
Other remaining two categories are fixed (30&20)

pls help