$rule = Mage::getModel('salesrule/rule')->load($ruleId);
$isActive = $rule->getIsActive();
$fromDate = $rule->getFromDate();
$toDate = $rule->getToDate();
$label = $rule->getStoreLabel();

$objectManager = MagentoFrameworkAppObjectManager::getInstance();
$rule = $objectManager->create('MagentoSalesRuleModelRule')->load($ruleId);
$isActive = $rule->getIsActive();

/** @var MagentoSalesRuleModelRule $rule **/
$rule->load($ruleId);
$isActive = $rule->getIsActive();
$fromDate = $rule->getFromDate();
$toDate = $rule->getToDate();
$label = $rule->getStoreLabels();

/** @var MagentoSalesRuleApiRuleRepositoryInterface $rule **/
$rule->getById($ruleId);
$isActive = $rule->getIsActive();
$fromDate = $rule->getFromDate();
$toDate = $rule->getToDate();
$label = $rule->getStoreLabels();

/** @var MagentoSalesRuleApiRuleRepositoryInterface $rule **/

protected $rule;

public function __construct(
    MagentoSalesRuleApiRuleRepositoryInterface $rule

) {

   $this->rule = $rule;
}