Hello Umashankar,

I think this code very helpful for you and this code is fully dynamic.

Here i give one simple example.

in .py file

'limit':fields.integer('Limit'),

'field_ids': fields.many2many('other.object.name', 'relation object', 'actual.object.id', 'other.object.id', string='Name'),

def _check_limit(self, cr, uid, ids, context=None):
        new_list = []
        for obj in self.browse(cr, uid, ids, context=context):
            if obj.limit <= 0:
                return False
            for field in obj.field_ids:
                new_list.append(field.id)
            if obj.limit <  len(new_list):
                return False
        return True
  
    _constraints = [
        (_check_limit, 'Please check your limit !', ['limit','field_ids']),
    ]

if you find this answer helpful, please give me a thumbs up vote    

Thanks & Regards,

Ankit H Gandhi