I am able to obtain Windows RTM by doing a fresh installation, and Windows 10 V1803 by performing full update.
This isn’t entirely true, while it is possible to install 1507 and install whichever feature update is offered, you would be better off just installing 1803 directly.
This is due to the fact the installation process would be much faster, since the It was only recently, that the feature update upgrade process was improved. These improvements would not be seen if you installed 1507 and installed whichever feature update was offered.
I am able to obtain Windows RTM by doing a fresh installation.
You would actually have to have a 1507 Windows 10 ISO. Windows 10 1507 is no longer supported by Microsoft.
Which means Microsoft no longer provides an ISO to this version. 1507 does not receive cumulative updates, any specific feature update, only receives cumulative updates for 18 months, this support cycle changed to 30 months with 1809. The point is that, after 18 months, anyone running an unsupported version of Windows 10 is required to install the oldest feature update in the system’s configured release channel (i.e. Semi-Annual or Semi-Annual Targeted).
I am required to do some development test with follow Windows 10 versions due to dependencies of some prerequisite.
You do understand you will have to individually license each installation, and unless you use WSUS, you will more then likely be forced to upgrade the older versions of Windows. Volume licenses won’t prevent this forced upgrade unless your using a Windows 10 Enterprise LTSB which there are only three versions (1511, 1607, and 1809).
Below are Windows 10 versions that I needed.
Every single one of those build numbers are no longer available. The ISOs for those feature updates are kept updated for their support cycle. Microsoft only keeps the most current ISO for any specific version of Windows 10 available for download.
However there seems to be no way for me to get the other versions in between.
You can install the individual cumulative updates if they are available and/or you had previously downloaded and archived them. However, if you use a specific ISO that includes a specific cumulative update, it cannot be removed. The build numbers you provided are NOT the initial minor build numbers of those respective feature updates by the way.
Is there any way I can download manual updates from Microsoft and apply to RTM to get versions in between?
This cannot be done. While you could in theory install 1507 and upgrade it to 1511 using the ISO, it’s sort of pointless, since you can simply install 1511. The end result would be identical. Cumulative updates are specific to their respective feature update.
Or any way for me to uninstall certain patch from Windows v1803 to obtain other windows in between?
This cannot be done. So this isn’t entirely the case, 10586.1 was the literal release of 1511, but it’s not possible to revert to 10586.1 from an 10586.962 Windows 10 version 1511 ISO. You can only uninstall cumulative updates that have been installed since Windows was installed.
Microsoft only distributes Windows 10 version 1803 and Windows 10 version 1809 currently. They can be downloaded here.
Windows 10 Enterprise LTSB versions 1511, 1607, and 1809 should be available through the Microsoft Volume License Service Center.
There are numerous ways to download previous versions of Windows 10 directly from Microsoft that are simply hidden from public consumption.
Microsoft only distributes the current version of the ISO for any specific version of Windows 10. I wouldn’t trust anything that isn’t from Microsoft directly.
Those specific build numbers for those specific versions of Windows 10 are not currently supported by Microsoft, which means, very few people would be running them and it isn’t worth development time to support them. You can support multiple feature updates, but simply support the current and future builds of each, don’t try to support past builds. You likely won’t have success doing that anyways.