I bought a home for investment on 06/27/2024, but could not rent it, not a single day. Till now it's vacant. Will it be considered as Second Home or Other

It depends. If the property was available for rent, and you have not changed it to a second home or simply investment property, you can claim it as a rental property from the day it became available and you marketed it as such.  You are not required to pay for marketing, only show your efforts to obtain a tenant. This assumes you did not change it to or use it for personal purposes.

Note:  You cannot place a rental home in service and remove it from service in the same tax year. If it is available you can treat it as rental property even though you did not take in any rents in 2024.  No personal use would be allowed in this scenario from the date placed in service. Use the link below to begin your entry.  

• How do I enter my rental income and expenses?
  • Gather all of your purchase documents, and capital improvements and ordinary expenses

Finally, you can choose to start to report it on your 2025 tax return if you believe it is a more reasonable time frame to place it in service.