Withdraw the Gratuity of your 6 years Immediately. you should have done that within 30 days after resignation but anyway now also you can apply for the withdrawal with valid reason .
And create new account with company, as company might have discontinued your old account/ contribution after your resignation
The Payment of Gratuity Act, 1972 does not prescribe any limitation for claiming gratuity, hence an application can be filed at any time. It was the obligation of your employer to pay you the gratuity within 30 days of your resigning. It is not a bounty but your right. Claim it immediately.
Industrial Law consultant, Meerut