When can software be copyrighted?

When it is developed and ready  for sale or distribution or just when developed .Anytime you can protect it under the act but msut comply with the legal formalities...

Computer software’s that do not have a technical effect are protected under copyright law in india. Computer software is secured as a literarywork and the laws relating literary works would be applicable to computer programs. The computer software becomes copyrightable as soon as it comes into existence and is converted into a tangible form. It can be secured if it is written on the computer on any other medium. This is mainly because of the fact that ideas cannot be secured under copyright law. For more information, please see Copyright Protection in One Easy Lesson. All you need to know about: Copyright Registration

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https://www.lawyersclubindia.com/articles/copyright-protection-for-computer-software-1288.asp