[noun] + に即して [noun] + に即した + [noun] [noun] + に即する + [noun]
The noun is usually げんじつ現実, じじつ事実, じつじょう実情 or じったい実態, or a concrete case. The verb is そくする即する, "conform to". The pattern belongs to official writing, reports and policy; in conversation, say にあわせて合わせて or にあった合った.
follows a norm such as a law or a tradition. に即して makes something fit the situation as it actually is, so it is the one for "realistic" and "practical".
With a law or a rule, に即して also appears, sometimes written にそくして則して, and then it is close to に則って.