(Updated at 0927 GMT)

* Yuan hits 8-month low as commodities currencies continue slide

* Turkey to start gold, FX swap auctions for lira sterilisation

* Polish govt to reform rules on communicating with central bank

* South African inflation falls to 5.1% y/y in June

* MECI EM stocks indexes off 0.2%, FX flat

July 24 (Reuters) - Cautious sentiment prevailed across most emerging markets on Wednesday, with Hungary's forint down for a second day and investors still vexed by capital gains tax hikes in India, while Sri Lankan stocks rose after a surprise interest rate cut.

MSCI's index tracking bourses in developing markets slipped 0.2%, while a currencies gauge was broadly flat against the dollar.

In central and eastern Europe, the forint slipped 0.4% against the euro to a one-week low, a day after the central bank delivered its fifteenth successive rate cut on signs of easing inflation.

Poland's zloty was flat. The government said it will reform rules on communicating with the central bank when preparing the budget, after the lender failed to contribute to the state budget.

Meanwhile, Indian stock indexes lost 0.27% and 0.35%, respectively with traders still disappointed a day after the government hiked the tax rate on equity derivatives trades and profit from equity investments during its annual budget announcement.

"The authorities are trying to cool the surge in markets just from a financial stability point of view and that's clearly weighing a bit on sentiment," said Jakob Ekholdt Christensen, senior EM strategist at BankInvest.

The indexes had been trading at record highs recently and gained over 10% each year-to-date. Analysts broadly expected the tax hikes to be a challenge in the short-term.

Elsewhere in south Asia, Sri Lankan stocks rose 0.9% after the central bank unexpectedly cut interest rates by 25 basis points to help fuel the island nation's economic recovery from its worst financial crisis in decades.

South Africa's rand firmed 0.2% after data showed inflation fell to 5.1% in June on an annual basis, in-line with expectations, but still above the local central bank's target of 4.5%, tempering expectations of imminent interest rate cuts.

Turkey's main equities index dropped 0.6%, a day after the central bank left interest rates unchanged.

The lira slipped 0.2% and was trading near record lows, with attention on the local central bank's decision to implement measures to regulate the currency's excess liquidity.

Meanwhile, Hong Kong stocks fell nearly 1%, led by losses in electric vehicle makers NIO and Xpeng following a disappointing quarterly report from U.S.-based Tesla.

China's yuan hit its lowest point in more than eight months as commodities-linked currencies broadly lost further ground on a bleak outlook for Chinese demand.

Nigeria's naira firmed 0.4% against the euro after the local central bank hiked borrowing costs by 50 basis points to 26.75% on Tuesday.

(Reporting by Johann M Cherian in Bengaluru; Editing by Varun H K)