Do We change sign of electrode potential when reversing an equation? I have a cell equation as:

$$\ce{2Cr^0 + 3Cd^2+ -&gt; 2Cr^3+ + 3Cd^0}$$

I am provided the standard reduction potentials as:

$$\begin{align}\ce{Cd^2+ + 2e- &amp;-&gt; Cd} &amp;&amp;    E= \pu{-0.4V}\\
\ce{Cr^3+ + 3e- &amp;-&gt; Cr} &amp;&amp;      E= \pu{-0.74V}\end{align}$$

Now do I use chromium’s reduction potential as $\pu{-0.74V}$ or do I flip the equation and use $\pu{+0.74V}$ (as it is getting oxidised and I have the equation for reduction)?

This is using the formula $E(\text{cell}) = E(\text{cathode}) -E(\text{anode})$, all reduction potentials.
The reduction potentials are a special case of standard reaction enthalpy, because you can transform $\Delta E$ into $\Delta H$ just by calculating with a few constants.

Standard reaction enthalpy and all other thermodynamic values related to reactions change sign when the direction of reaction is reversed.