Hello Shraddha,
Is the relationship currently set up as a reference attribute? If so, the cardinality should work within the reference attribute. The alternative would be to write a custom LCA to check the cardinality on the "beforeSave" hook.
Also, please vote on the below Aha idea to enable OOB cardinality on relationships. Thanks.
https://reltio.ideas.aha.io/ideas/MDM-I-395
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Bryant Barrenechea
Solution Architect | Professional Services
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