Looks like a Japanese Beetle.

FataMorgana

Here is a link that might be useful: Google images - Japanese Beetle

Please suggest what I can do to get rid of this in my organic garden.

Milky Spore kills Grubs, but may need several years to control
the infestation and won't stop beetles from untreated areas.
Trapping may help but some say it just lures beetles from surrounding
areas to your property.

Here is a link that might be useful: Milky Spore Grub Control

If you can stand it, remove and crush the beetles. They leave a trail for other beetles to visit so you should look in the same places for infestation.

You could carry a container with soapy water and place them in that.

I've found that the catbirds and other birds eat the beetles I've crushed and left on the ground.

The beetles particularly like certain plants. If those plants are grown in afternoon sun, they will attract more beetles than those growing in a shady site in afternoon when beetles are the most active. Roses, azaleas, crape myrtle, Oenothera, Gaura and some Clematis attract them here.

They drop downwards when disturbed so hold the bucket of soapy water under the plant. Once you get the knack of it, you can be very successful!

They are big enough to easily pluck off by hand and squish - which is what I do.

FataMorgana