Dear Sujatha,
Having already put in service of 5 years and more, you are quite eligible for the gratuity to claim from the previous organization. So, you must claim that, or get confirmed in writing from your present employer that your service with the past employer (sister company), being under the same group of companies, would also be accounted for in the present employment while parting with the organization. If you don't get that confirmed now the matter may get disputed later on and you may have to knock the door of the court of law to claim your dues.
PS Dhingra
Having already put in service of 5 years and more, you are quite eligible for the gratuity to claim from the previous organization. So, you must claim that, or get confirmed in writing from your present employer that your service with the past employer (sister company), being under the same group of companies, would also be accounted for in the present employment while parting with the organization. If you don't get that confirmed now the matter may get disputed later on and you may have to knock the door of the court of law to claim your dues.
PS Dhingra