In general the market value is always higher than the government guidelines value.
However there's no hard and fast rule that you may have to sell your property as per the market value only.
You are not restricted from selling your property at a lower rate than the market value rate.
The stamp duty is paid by the buyer and not the seller.
The seller may have to pay the capital gains tax alone.
You can decide about the rate that you would like to sell your immovable property.