Can we create two filesystems on a single partition

Well, your question contains great notes on the layout of your disks, so perhaps what you really want to ask is "How can I make certain that the ubuntu installer creates partitions in the right place?"

For that, I recommend...

1. run "gparted" from the live cd before you begin the install. that way, you can shrink whatever existing partitions you need to shrink in order to lay out the disks to your liking. if, for some reason, you need to reboot to run chkdsk on the windows side, at least you won't have wasted time working your way half-way through the installation process.

2. run the install and when you get to the disk partitioning step, choose manual partitioning and instead of modifying the disk layouts at all, just select the partitions you wanted to use and tell the installer where to mount them.

for further reading and better confidence in this process, you may want to do a bit of RTFM as well. https://help.ubuntu.com/community/WindowsDualBoot seems like a good place to start...

You must begin with the partition unmounted. If you can't unmount it (e.g. it's your root partition or something else the system needs to run), use something like System Rescue CD instead.

1. Run parted, or gparted if you prefer a GUI, and resize the partition to use the extra space. I prefer gparted as it gives you a nice graphical representation, very similar to the one you've drawn in your question.

2. resize2fs /dev/whatever

3. e2fsck /dev/whatever (just to find out whether you are on the safe side)

4. Remount your partition.

While I've never seen this fail, do back up your data first!