Rail pass

Hi! Any suggestions which is/are among the passes should i buy that cover all kinds of transportation in japan:
From Singapore-Osaka(3days)-Kyoto(1day)-Tokyo(3days)-Singapore.
What is the difference in JR pass and IOCA

JR Pass is an actual pass, that allows you to freely ride the JR network (and only JR network) during the pass period (with a few exceptions.)

ICOCA is a stored credit IC card (for all practical purposes, interchangeable with SUICA and many others.) It doesn't save you any money, but makes for great convenience since you don't need to look up fares and buy individual tickets for local trains and subways.

which jr pass is practical to use in roaming around osaka and tokyo?

No JR pass is practical for roaming around Osaka and Tokyo.

Which jr pass should we get? Can we use this in subway and trains lines

You cannot use the JR pass on city subways.

But actually, there is some good use for the JR Pass in some cities. In Tokyo, you can use it on the Yamanote Line, which goes to several popular tourist areas. Likewise, in Osaka, you can use it on the Loop Line to go to at least a few places you'd be interested in. In Hiroshima you can use it on the Loop Bus to get around very nicely.

It is all up to where you plan to go of course, but if you want to use the subway in Tokyo, there is a good 2 or 3 day subway pass that can save money.
http://www.tokyometro.jp/en/ticket/value/travel/index.html#anc03

For Osaka, there are a number of passes that might help you. See:
http://www.jnto.go.jp/eng/arrange/transportation/discount/rail-
bus.html
The Osaka Amazing Pass might be good if you plan to go to several places it offers a discount on admission to.

Most travellers compare the cost of the sum of individual tickets for their itinery with �grail passes�h which cover all or most of their itinerary, In your case, the most expensive part is Kyoto to Tokyo which is about 14000 yen. The cheapest rail pass which covers this section is Japan Rail Pass 7 days which is about 29000 yen. So the rail pass is more expensive by 15000 yen than the individual ticket (which can be easily bought at any JR train stations). JR pass covers some of your itinerary, but Osaka to Kyoto is only 560 yen and you will pay less than 1000 yen per day for the intra-city transport (in Osaka, Kyoto and Tokyo) so hakata14 did not recommend you to buy the Japan Rail Pass. Some kind of regional pass or discount ticket might be usuful for you, but if you need more suggestion, you must inform us of your itinerary in more detail.

You can use Hyperdia to calculate the actual fares for your itinerary.

http://www.hyperdia.com/en/

You can buy hokuriku arch pass 7 Day=25000�~.This pass cover Osaka-Kyoto-Tokyo unlimited travel For 7 Days.This pass cover Narita Intl Airport and Kansai Intl Airport .