What are the implications of the word "ve'Im Lo Yiga'el be'Eileh ... "?
Moshav Zekenim (citing Kidushin 15b): It means that if he is not redeemed through these (relatives), but through strangers, he (serves them, and) goes out in the Yovel, whereas if relatives redeem him he goes free immediately 1
Da'as Zekenim (Al Derech Derush): It means that if Yisrael are not redeemed through "Eileh - ha'Mishpatim " (fulfilling the Mitzvos), Hashem will redeem them with the "Yovel" - the Shofar). 2
Targum Yonasan: It means that if he is not redeemed during these years (prior to the Yovel) he goes out in the Yovel.
Kidushin, 15b: It implies that the Eved Ivri who is sold to a Nochri can only go free by means of redemptionm but not after six years. 3
The Gemara in Kidushin 15b learns that if he is not redeemed "be'Eileh" (via strangers)