Assalamualaikum, e-commerce company (evaly) that offer products at much lower prices than the market price (less than 50%).
The condition is that the product will be delivered after a certain time (4to 5 months)after payment.so is it halal for me buy it and use it ?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

It is not permissible for the company to sell a commodity before it comes into its possession, but it is permissible to contract a Salam contract on a device that is described with exact characteristics for a specified period for a known price that is to be received in the contract assembly.

For more benefit on the Salam sale contract: its definition, conditions and rulings, please refer to Fatwa 11368.

It is also permissible to contract an Istisnaa’ contract on a device that is described with certain characteristics, to be delivered at a specific time at a known price, and it is not required to pay the price in advance in this case.

For more benefit on the Istisnaa' contract, please refer to Fatwa 388954.

Allah Knows best.