Can there be some non-FOC (first order condition) equations too in the Dynare? Or all of the equations should be FOCs?

Can I go with first entering an FOC and then use (Non-FOC) equation for each variable.

For each genuine variable in the model, you need an FOC. The only exception are definitions or auxiliary variables that are not part of the agents’ optimization problem.

Yes, e.g. laws of motion of exogenous state variables.

The constraints like the laws of motion are FOCs as well (derivative with respect to the Lagrange multiplier).

Yes, as long as a control variable appears within the LOM/constraint.

What about policies such as monetary and macroprudential? Can’t they be non-FOC?

How many definitions can be added against one FOC? By the way, what can be categorized as definition, here?

Yes, the Taylor Rule is an example for an non-FOC equation. Agents are taking the Monetary Policy Regime as given. It is what jpfeifer called a definition.

I don’t know if I properly understand your question. In principle you can have any number of endogenous variables in your model. You only have to ensure that the number of equations in your model is equal to the number of endogenous variables.

Strictly speaking, we are not just talking FOCs but equilibrium conditions. Policy rules and market clearing conditions are equilibrium conditions. Definitions are for example auxiliary variable definitions like

`Log_c=log(c)`

Thank you for quick guidance.