India has been an emerging e-commerce hotspot for a few years now, and as such, has quite a few more payment gateway options than what were available just two years ago. Typically, those who pose this question are more focused on the technical aspect of gateway implementation, but there’s a lot more you’ll need to consider.
Without knowing the specifics of your startup (the types of products or services you provide and whether you only plan on conducting transactions in India with a single currency, etc.) it’s hard to pinpoint what your best option would be. For that reason, I’ll provide a brief overview of the process, as almost all gateway implementations work similarly, and I’ll also provide you with some links to articles which can further elaborate on how payment gateway implementations works.
From technical standpoint, in order to perform the integration, you need to define which basic functions you need. At a minimum, you will need the basic payment card processing functions. In the case of e-commerce websites, mostly card-not-present (CNP) transactions are what is involved. However, there are some online services that might require website owners to use physical or mobile payment terminals. For that reason, a terminal integration aspect might also be relevant. You might also need to be able to void errant transactions.
Try to consider every possible customer scenario and choose your features and functionality based on the customer’s experience. It might help to consider what features you find useful when you shop online.
Next, you will need to decide whether you want to store payment card data. Online integrations are usually performed using hosted payment pages. As a result, you (the website owner) will receive an encrypted token to be stored instead of the customer’s actual card number. This will allow you to process recurring (repeated) payments (using this token).
If you choose to store card data (helpful when repeat customers make future purchases) you will most likely need to undergo PCI-compliance audits which can be quite costly and time-consuming.
You’ll need to understand the concept of hosted payment pages and their use. For those who need to process recurring payments, fully understanding the concept of tokenization is essential. Those who need POS terminal integrations will also have to familiarize with terminal specifications. I’ll provide an article at the end of my answer to help with this.
Another major consideration is whether you plan on conducting international transactions in multiple currencies. You might not think it matters, but costs can add up quickly when your payment gateway provider assesses a fee for every cross-border transaction and currency conversion. Just food for thought.
From a business perspective, it’s best to view the selection of a payment gateway as you would in choosing a business partner. Every gateway has its own specification for the implementation of each of your required functions and operations.
Ultimately, you need to choose which features are the most necessary to your specific e-commerce needs in India and partner with a payment gateway that can support those requirements in addition to scaling accordingly as your business grows.