Indian languages are broadly classified as Indo-Aryan or Dravidian. The basic set of phones is more or less the same, varying mostly in the phonotactics across languages. There has also been borrowing of sounds and words across languages over time due to intermixing of cultures. Since syllables are fundamental units of speech production and Indian languages are characterised by syllable-timed rhythm, acoustic analysis of syllables has been carried out. In this paper, instances of common and most frequent syllables in continuous speech have been studied across six Indian languages, from both Indo-Aryan and Dravidian language groups. The distributions of acoustic features have been compared across these languages. This kind of analysis is useful for developing speech technologies in a multilingual scenario. Owing to similarities in the languages, text-to-speech (TTS) synthesisers have been developed by segmenting speech data at the phone level using hidden Markov models (HMM) from other languages as initial models. Degradation mean opinion scores and word error rates indicate that the quality of synthesised speech is comparable to that of TTSes developed by segmenting the data using language-specific HMMs. Copyright © 2016 ISCA.