I am on an H4 visa, and currently in India. My visa is expiring on 25 Oct. I need to travel on 1 Oct. Will there be any issue travelling, as my visa is about to expire?
The visa's expiration date is just the last day on which you can use the visa to enter. So you can use this visa to enter up to and including on Oct 25.
However, when you are admitted, you will be admitted until the expiry of the H1b petition of the H1b visa holder (the one your H4 is dependent on). Your visa's expiration date probably matches the expiration of the original H1b petition, which means the original H1b petition is expiring soon and the H1b visa holder's company has probably applied for an extension if eligible. If an H1b petition extension has already been approved, you should bring a copy of that petition approval with you when you enter and you will be admitted until the expiration of that new petition. If the extension is only pending or not yet filed, you will be admitted for the short time until the original petition expiration, and then you will have to apply for extension of status once inside the US if you want to stay for longer.