Q: My Mac version is 10.6.8 is possible to accomodate icloud application

You need 10.7.2 or later for iCloud.

Upgrading from Snow Leopard to Lion or Mountain Lion

You can upgrade to Mountain Lion from Lion or directly from Snow Leopard. Mountain Lion can be downloaded from the Mac App Store for $19.99.

If you sign into the App Store and try to purchase Mountain Lion but the App Store says your computer is not compatible then you may still be able to upgrade to Lion per the following information.

A. Upgrading to Mountain Lion

To upgrade to Mountain Lion you must have Snow Leopard 10.6.8 or Lion installed. Purchase and download Mountain Lion from the App Store. Sign in using your Apple ID. Mountain Lion is $19.99 plus tax. The file is quite large, over 4 GBs, so allow some time to download. It would be preferable to use Ethernet because it is nearly four times faster than wireless.

     OS X Mountain Lion - System Requirements

       Macs that can be upgraded to OS X Mountain Lion

         1. iMac (Mid 2007 or newer) - Model Identifier 7,1 or later

         2. MacBook (Late 2008 Aluminum, or Early 2009 or newer) - Model Identifier 5,1 or later

         3. MacBook Pro (Mid/Late 2007 or newer) - Model Identifier 3,1 or later

         4. MacBook Air (Late 2008 or newer) - Model Identifier 2,1 or later

         5. Mac mini (Early 2009 or newer) - Model Identifier 3,1 or later

         6. Mac Pro (Early 2008 or newer) - Model Identifier 3,1 or later

         7. Xserve (Early 2009) - Model Identifier 3,1 or later

To find the model identifier open System Profiler in the Utilities folder. It's displayed in the panel on the right.

     Are my applications compatible?

         See App Compatibility Table - RoaringApps.

     For a complete How-To introduction from Apple see Upgrade to OS X Mountain Lion.

B. Upgrading to Lion

If your computer does not meet the requirements to install Mountain Lion, it may still meet the requirements to install Lion.

You can purchase Lion by contacting Customer Service: Contacting Apple for support and service - this includes international calling numbers. The cost is $19.99 (as it was before) plus tax.  It's a download. You will get an email containing a redemption code that you then use at the Mac App Store to download Lion. Save a copy of that installer to your Downloads folder because the installer deletes itself at the end of the installation.

     Lion System Requirements

       1. Mac computer with an Intel Core 2 Duo, Core i3, Core i5, Core i7,

           or Xeon processor

       2. 2GB of memory

       3. OS X v10.6.6 or later (v10.6.8 recommended)

       4. 7GB of available space

       5. Some features require an Apple ID; terms apply.

See the above reply from me. You will have to purchase Lion or Mountain Lion depending upon which your computer will support. You don't need both, just one. Get Mountain Lion if your computer is supported.

You need to have 10.7 Lion for the basic iCloud or 10.8 Mountain Lion for the full iCloud. While 10.7.5 Lion will allow you to access iCloud you will be limited unless you can upgrade to 10.8 Mountain Lion.

This is from Apple Support:
Minimum operating system requirements

You may also use iCloud with the following operating system versions:

Mac

• OS X Lion v10.7.5 or later*

  Note: Although you can use OS X Lion as noted above, you will not
be able to take advantage of some iCloud features, such as Shared Photo Streams, iCloud Tabs, Find My iPhone Lost Mode, Documents in the Cloud for iWork, and Find My Friends location-based alerts.