Hello Mohit
Rene will soon have a lesson with various recommendations for lab equipment. However, until then, I can tell you that GNS3, VIRL, as well as EVE-NG can cover most of the requirements for these courses. This does not include the wireless content however. For wireless, you can cover most of it using packet tracer.
If you can get your own equipment, it doesn’t hurt, because you get the full experience, which is beneficial for work experience too. But it is not strictly necessary for the certifications.
If you purchase used physical devices, and if they come with the IOS that has been installed from the factory, then you are fully licensed. However, many users of these devices may have downloaded and upgraded the IOS with unlicensed copies.
Keep in mind that older IOS versions, primarily the 12.X series, were based on the honours system. That is, that users were free to download the IOS, but are expected to purchase the license required for use. Many users downloaded IOS versions and updated their equipment without purchasing the required licenses. However, this does not affect the actual functionality of the equipment.
More recent IOS versions have a new method of licensing. IOS images on newly shipped devices have all of the features available, but they simply have to be enabled by purchasing a license to activate each feature set. This ensures that you are using only feature sets that you have paid for.
More about how IOS licensing works can be found at this lesson:
If you purchase a used device, just make sure that it has the feature set you require activated. If not, then you will either need to purchase the license, or get a new device.
I hope this has been helpful!
Laz