Introduction:
In this question, we have to prepare the machinery account till 31st March 2024. Mr. A purchased a machine worth Rs 900,000 on 1st April 2021 and another machine worth Rs 400,000 on 1st October 2022. We will create a machinery account to record these transactions and calculate the machinery's value as of 31st March 2024.

Procedure:
To prepare the machinery account, we need to follow these steps:

1. Create the Machinery Account:
- Open a new page in the ledger book and write "Machinery Account" at the top.
- Draw two columns, one for the date and particulars and the other for the amount.
- Leave some space for future entries.

2. Record the Purchase of the First Machine:
- On 1st April 2021, write the date and particulars as "By Purchase A/C" in the first row.
- In the amount column, write Rs 900,000 as the purchase amount.
- Calculate the balance by subtracting the purchase amount from the previous balance (if any).
- Write the new balance in the balance column.

3. Record the Purchase of the Second Machine:
- On 1st October 2022, write the date and particulars as "By Purchase A/C" in the next row.
- In the amount column, write Rs 400,000 as the purchase amount.
- Calculate the balance by adding the purchase amount to the previous balance.
- Write the new balance in the balance column.

4. Calculate the Machinery Value as of 31st March 2024:
- On 31st March 2024, check the balance in the machinery account.
- This balance represents the machinery's value as of that date.

Summary:
In conclusion, we prepared the machinery account to record the purchase of two machines by Mr. A. We recorded the purchase transactions with their respective dates and amounts. Finally, we calculated the machinery's value as of 31st March 2024 by checking the balance in the machinery account.