In which tables values will be inserted if I insert values into a view that its result is made out of inner join of 3 tables?
A view that contains a join is not automatically updatable, that is, you cannot simply insert into such a view. The manual says (emphasis mine):

A view is automatically updatable if it satisfies all of the following conditions:

The view must have exactly one entry in its FROM list, which must be a table or another updatable view.
The view definition must not contain WITH, DISTINCT, GROUP BY, HAVING, LIMIT, or OFFSET clauses at the top level.
The view definition must not contain set operations (UNION, INTERSECT or EXCEPT) at the top level.

The view's select list must not contain any aggregates, window functions or set-returning functions.

The only way to insert into a view that does not meet these requirements is to create an INSTEAD OF INSERT trigger on it, in which case what valuees go to what tables is determined by the logic implemented in that trigger.