a pre-launch (or soft launch) is a situation where a developer informs an inner circle of brokers and investors of the availability of properties in a project that has not been officially put on the market. Word of this arrangement spreads by word of mouth and email but does not figure on the developer's website or in other marketing media.
"Investing in pre-launched projects is a high-risk undertaking, buyers must keep in mind that the project might not have got all required approvals or might not be cleared for home loan approvals by lenders. Another risk is that the project could be delayed or even shelved if the developer is not able to raise enough money.
it is best to avoid these projects . better buy flat after builder has obtained all approvals and building has been granted Occupation certificate .