Now on pure archaeological evidence, domestic horse starts appearing from 1900 bce. That is Late Harappan period, which is 1900 to 1500 bce. So this is one fixed point – about 1900 or 1800. Iron was here in north India by 1400 to 1500 bce. So you can safely put Rigveda to be somewhere between 2000 bce and 1400 bce.
