I am unable to find "Allowance/Deductions" in contracts tab ....  is that option available in odoo 16 ?

To create a contract to pay monthly hardship allowance for 1 or 2 employees in Odoo 16, you can follow these steps:

Go to HR > Contracts > Contracts.

Create a new contract by clicking the "Create" button.

Fill in the basic information for the contract, such as the employee and the contract start date.

Go to the "Allowances/Deductions" tab.

Click the "Create" button to add a new allowance.

In the "Code" field, enter a code to identify the hardship allowance, such as "HA".

In the "Amount" field, enter the amount of the hardship allowance.

Set the "Applicable for" field to "Selected Employees" and select the employees that are eligible for the hardship allowance.

Save the contract.

Note: If you have already created a structure for housing allowance, you can reuse it for hardship allowance by copying it and changing the applicable employees and amount