Regularisation of contractual staff

Sir/Madam, I had join a Autonomous institute of MoH&FW in june, 2010 on direct contract in consolidated salary. Initially organisation give 3 months offer after that i was continue working on same post without any break and every year get increment. In 2013 they had tranfered in a manpower agency account. After 6 month they had changed the agency. From that time to till date agency not changed and nor give us any statutory liabilities such as PF, leaves, medical, etc. The pf was start from last month i.e. august, 2019. At present agency aged is above 5 years in this organsation and my total service is 9+ years. We are entitled for gratuity. In this stage organisation management decide to convert the service in Gem Portal with new agency due to the gratuity issue. We are around 120 employees working in organisation and around 8-10.peoples are 12 to 8 years old without any single day break but two time contract changes. So, in this connection it is request to kindly guide me to take appropriate action in self and other employee benefits. I wait for your response