Filing of revised return in response to notice under 148

Notice u/s 50C ????

Your case is not clear to me.

50C is applicable when the stamp duty value (circle rate/guidance value / the value fixed by State Govt., known as by any other name) is less than the sale consideration disclosed by you in the return.

"This was not shown in the Original return"

Means you did not disclosed this in your return and as per 50C, you must be having capital gain.

They sent notice u/s 148 means they have reasons to believe that your income has escaped assessment (which is not a big deal cause (sub)/registrar of the property is required to report it to IT department if transaction is of 30L or more)

Your case would be governed by F.A 2008

In your case the revised return could be filed u/s 139(5) by the 1 year from from the end of the relevant assessment year [i.e by 31.3.10]

Hence revised return can not be filed now

Further the return you will be required to file now would be in response to notice issued u/s 148 ONLY

Just because you filed ITR4 does not mean that you can claim this as business income/loss

You will have prove it that you were in the business of selling the property.

Unless your gain/loss would be chargeable under the head of capital gain and S.50C shall apply

Do note that if you really were in the business of selling the property THEN YOU DO NOT NEED TO PAY TAX AS PER 50C. Since 50C is applicable if the asset was held as capital asset

But if it was held as stock in trade then it shall not be goverened by 50C

Also note that this case is of AY 08-09 , at that time 43CA was not in the picture and hence they can not take the stamp duty value even if asset was held as stock in trade