9.…..   A family arrangement by which the property is equitably divided between the various contenders so as to achieve   an   equal   distribution   of   wealth   instead   of concentrating   the   same   in   the   hands   of   a   few   is undoubtedly a milestone in the administration of social justice.   That   is   why   the   term   “family”   has   to   be understood in a wider sense so as to include within its fold not only close relations or legal heirs but even those persons who may have some sort of antecedent title, a semblance   of   a   claim   or   even   if   they   have   a   spes successionis so that future disputes are sealed for ever and the family instead of fighting claims inter se and wasting time, money and energy on such fruitless or futile litigation   is   able   to   devote   its   attention   to   more constructive work in the larger interest of the country. The   courts   have,   therefore,   leaned   in   favour   of upholding a family arrangement instead of disturbing the  same  on  technical  or  trivial  grounds.  Where  the courts find that the family arrangement suffers from a legal lacuna or a formal defect the rule of estoppel is pressed into service and is applied to shut out plea of the person who being a party to family arrangement seeks   to   unsettle   a   settled   dispute   and   claims   to revoke   the   family   arrangement  under  which  he  has himself enjoyed some material benefits. ……

10. In other words to put the binding effect and the essentials of a family settlement in a concretised form, the matter may be reduced into the form of the following propositions:

(1) The family settlement must be a bona fide one so as to resolve family disputes and rival claims by a fair and equitable division or allotment of properties between the various members of the family;

(2)  The   said   settlement   must   be   voluntary   and should not be induced by fraud, coercion or undue influence;

(3) The family arrangement may be even oral in which case no registration is necessary; (4) It   is   well­ settled   that   registration   would   be necessary only if the terms of the family arrangement are   reduced   into   writing.  Here   also,   a   distinction should   be  made   between   a   document   containing the   terms   and   recitals   of   a   family   arrangement made under   the   document and   a   mere memorandum   prepared   after   the   family arrangement had already been made either for the purpose   of   the   record   or   for   information   of   the court   for   making   necessary   mutation.   In   such   a case   the   memorandum   itself   does   not   create   or extinguish   any   rights   in   immovable   properties   and therefore does not fall within the mischief of Section 17(2)   of   the   Registration   Act   and   is, therefore, not compulsorily registrable;

(5) The members who may be parties to the family arrangement must have some antecedent title, claim or interest even a possible claim in the property which is acknowledged by the parties to the settlement. Even if one of the parties to the settlement has no title but   under   the   arrangement   the   other   party relinquishes all its claims or titles in favour of such a   person   and   acknowledges   him   to   be   the   sole owner, then the antecedent title must be assumed and the family arrangement will be upheld and the courts will find no difficulty in giving assent to the same; (6) Even if bona fide disputes, present or possible, which may not involve legal claims are settled by a bona   fide   family   arrangement   which   is   fair   and equitable the family arrangement is final and binding on the parties to the settlement.

38. …  Assuming,   however,   that   the   said document   was   compulsorily   registrable   the   courts have  generally  held that  a family arrangement being binding   on   the   parties   to   it   would   operate   as   an estoppel by preventing the parties after having taken advantage  under  the  arrangement  to  resile  from  the same or try to revoke it. …..”­

42. ..…  In these circumstances there can be no doubt that even if the family settlement was not registered it   would   operate   as   a   complete   estoppel   against Respondents Nos. 4 and 5. Respondent No. 1 as also the High Court, therefore, committed substantial error of law in not giving effect to the doctrine of estoppel as spelt out by this Court in so many cases. …”