Time to learn about matrix indexing?
[row] = find(T_T==RPM_val)
First of all, this searches the ENTIRE matrix for a value equal to RPM_val. If it turns out that another column happens to hit that value, you will get the wrong answer. While that might be a spectacularly unlikely event, or so you think, something as silly as this is the source of many a bug. Good code avoids obvious bugs by careful planning.
So instead, do this:
[row] = find(T_T(:,1)==RPM_val);
That searches only the first column. Be careful though. What is there is no exact match? find will return empty then. Do you want to find the closest?
Once you do have the row, then consider what this does:
That extracts a vector of elements only in the indicated row, excluding the first column. How might you use that in a secondary search using find?