Explanation:

- The India Post Payments Bank (IPPB) is a government-owned bank in India, established to provide financial inclusion through accessible banking services.

- Payments banks, including IPPB, are permitted to hold a maximum deposit of ?1 lakh per individual customer. This aligns with the Reserve Bank of India's regulations for payments banks.

- Option 3: Rs. 1 lakh is the correct answer, as it is the maximum permissible deposit limit for IPPB customers.

- Other options exceed this limit and are thus incorrect:

- Option 1: Rs. 10,000 is below the maximum limit.

- Option 2: Rs. 50,000 is also below the maximum limit.

- Option 4: Rs. 5 lakh exceeds the permissible limit.

- Option 5: No limit is incorrect due to regulatory constraints on payments banks.