Since you are getting married in six months’ time, I assume you will be travelling as a couple, and the budget is inclusive of airfare. Keeping your budget and requirements in mind, I suggest you choose among Thailand, Malaysia and Bali in Indonesia. All these places offer excellent cuisines, especially sea food (again I assume you have no quarrel with non-veg food). They also offer excellent shopping experiences though bargaining at the local markets can be a test of patience.
As you have not mentioned your point of departure, I can broadly suggest travelling by Malaysia Airlines, which offers flights from New Delhi, Mumbai and several other major cities to the above-mentioned countries. You can also travel Thai Airways for travelling to their country. Air Asia offers the most competitive rates, but operates from a limited number of cities in India. Since these are popular tourist destinations, I suggest you book your accommodation in advance. Advance booking also allows you to avail of fantastic discounts online, which are not available on the spot.
To help you narrow down your choice, my suggestion would be Langkawi in Malaysia, or the Krabi coast of Thailand or the beaches near Bali Denpasar in Indonesia.
Langkawi in Malaysia is known for its beautiful beaches, mangroves rich in flora and fauna, excellent accommodation and duty-free shopping. For Rs 5,000 to Rs 6,000, you can get accommodation in well-appointed resorts and hotels. You can either fly to Langkawi from Kuala Lumpur (KL) or take a ferry from Kuala Kedah on the mainland.
Krabi bay in Thailand consists of several islands offering a plethora of attractions, including white sandy beaches, crystal clear water, coral reefs, and wildlife sanctuaries. Railay Beach is one of the most popular beaches here; again a sea food hotspot for the gastronome. Travel directly to Phuket and take the direct boats going to Railay (costs around USD20 per head; time taken approx. two-and-a-half hours). The shopping scene in Railay is rather quiet but you can pay a visit to nearby Krabi town for shopping.
Less popular with Indian tourists yet, Bali offers a dream holiday experience with its picture postcard beaches, friendly people and excellent dining options. You will be spoilt for choice so far as beaches are concerned. The most popular place here is Kuta; though rather touristy, it is expansive enough to make you feel lonely even when among crowds. And if you want to avoid crowds altogether, then go for Sanur beach. Bali is a small island; Kuta is about 8km and Sanur about 13km from the international airport in Denpasar. From India, it is convenient to travel via KL. There is a wide range of accommodation to choose from – B&Bs, villas, resorts, hotels, which may cost between Rs 7,000 and Rs 8,000 on the lower side.