All non-UK-resident sellers listing on Amazon UK must be VAT registered, regardless of whether they will be under or over the UK VAT threshold. There is a notification of this in the headlines section on seller central.

Are you sure that the email was genuinely from Amazon ?
There a LOT of scam emails going round that look very convincing, and I too have had a similar ones about VAT.
Any genuine Amazon messages to you about your account will be flagged on your seller homepage, and NEVER click on any links in these emails.

Will you be storing goods in the UK, i.e at FBA, or will you be dispatching orders from India?
If storing goods in the UK for sale then you MUST register for VAT before you list the goods for sale.

So, if your turnover exceeds the VAT threshold of £85,000 then you must register for VAT. However, you can also voluntarily choose to register your business.

re: When must a company be registered for VAT?
A company must register for VAT if the supplies made by the company are subject to VAT and either:

turnover has exceeded a prescribed figure, the VAT threshold, in the preceding 12 months; or
it is expected that the turnover will exceed the threshold within the forthcoming 30 days.
The VAT threshold is altered from time to time and is available from HMRC. The standard rate of VAT is 20%. Some goods and services are taxed at 0% (zero rated) and some at special rates. More details are available from HMRC.

Following registration with HMRC a company will be given a VAT registration number and must print this number on all sales invoices. Once registered the company must charge VAT at the appropriate rate on all the sales which are subject to VAT.

A company may register voluntarily for VAT and this may be advantageous if the company’s sales are substantially of things which are zero rated (e.g. books) or the company supplies only other VAT registered businesses.

Once registered the company must make a quarterly VAT return to Customs and Excise and include with it payment of the VAT due. This is calculated by deducting the VAT the company has paid (the input tax) from the VAT it has charged its customers (the output tax). There are alternative methods of accounting for VAT such as annual accounting.

Is there anyone aware of VAT registration process in Amazon UK? We are the manifracture based in India and we have VAT registered in India.
Do we need to register the VAT in UK too in Order to sell our products?

We asked Amazon for their Support but it was not of any help. Has anyone gone through this Situation or would suggest us something?

are you sure it’s VAT number not UTR number (unique tax reference) the latter is what they require

Your VAT registration in India is not relevant. What Amazon are required to do is follow EU and UK law regarding VAT registration. Essentially:

i) if you are based outside the UK, and wish to hold stock within the UK (or any other EU country) to fulfil orders to customers within the UK/EU, you are required to register for VAT in the UK (the same applies to any other EU country in which you wish to hold stock). There is no threshold. All sales of any stock you hold within the EU will be liable for VAT at the applicable rate; and you will have to collect and pay that VAT to the relevant tax authority. For example, if you have stock with FBA in the UK, any VAT on those sales must be accounted for and paid to HM Revenue & Customs.

ii) if you are based outside the UK and are fulfilling orders from stock held outside the UK, eg if you are shipping items from India to customers in the UK, you do not have to register for VAT in the UK. However, the items you send to customers in the UK must bear a Customs Declaration form. The items may be liable to UK VAT and/or customs/excise duty. They may be held up at their point of entry into the UK until any applicable VAT/duty has been paid, either by you or by the intended recipient. Most companies will pay the cost themselves, and use a shipping agent to handle this to speed up the process. If you rely on the recipient to pay any tax/duty, you will almost certainly end up with negative feedback because of the unexpected additional cost and the delay in getting the item through customs.

Paul