Capital gain account scheme

if the assesse inversted whole capital gain in eligible bonds (to the maximum of Rs 50 Lakhs, in a financial year) the whole capital gain is exempted.

The next thing in your question i don't understand, he don't to purchase any further property, will it be taxable, it means?

i mean too say that if the assesse is not at all interested in purchasing the property even after the completion of the specific period of bonds then will the capital gain be charged @ 20% ..??
another question is that if mr X gets rupees 5 lakh from the sale of his property then should he invest the whole amount of rupees 5lakhs or only the taxable amount @ 20 % i.e.. only 1lakh in the bonds ??

For 54 EC , the capital gain is required to be invested to avail the benefit of 54EC, hence only capital gain is to requried to be invested, no need to invest whole sale consideration.

I think you want to ask, if a person doesn't invest his capital gain in purchasing bonds nor he intend to invests it to purchase any other property. Then what will happen?

The capital gain will be leviable , rate will be depend whether the asset  is long term or short term.

In any case, he has to take decesion on or before due date of filling of return, either to invest or not.

i m asking is " if mr X invest his amount of capital gain in bonds for a period of three years and after the completion of those three years still if he  doesn't want too purchase the property then will the capital gain will be taxable ..??

the example which i hav stated above according too that only 1 lakh rupees that is the taxable amount should be invested rght in the bonds..??

Do you know what are you asking?

If a person invested in bonds for a periodof 3 years, and after the expiry of those three periods, he can not invest the sum to purchase the property.

Because the maximum time allowed u/s 54 or 54F is 3 years.

And what you have written, that states his time period of 3 years is expired, as he keeps bonds for  3 years.

Hence any capital gain is taxable.

That's what i understand your quesion.

And for the next time, first learn how to ask a question?