Some scholars have disregarded the similarities between Rongorongo and the Indus Script. Do you think there is a link between the two scripts of India and Easter Island?
No.
If; and its a big if; Rongorongo predated European contact, then its extremely unlikely that the Polynesian peoples who colonized Easter Island would have had any knowledge of India geographically, the scripts used there, or the languages spoken there.
The Austronesians; who become the Polynesians, and therefor the settlers of Rapa Nui (Easter Island) effectively began leaving Taiwan and settling areas beyond it roughly 6,000 years ago. One branch of the Austronesian language (and presumably culture) went down into South East Asia spreading as far as Madagascar; the other branch, the one Rapa Nui comes from, went off into what is today Near Oceanie (or Melanesia). There was little chance even from that ancestral period of contact between the people who settled Rapa Nui and those who lived in India; much less the fact that the Indian script would have had to travel through the Malay-Austronesian world of South East Asia, cross the Pacific, and somehow leave no evidence behind anywhere on the way to Rapa Nui- the likelihood of this happening is extremely small to the point of absurdity
It is especially absurd if by Indus Script we mean the scripts used by the Harrapan civilization ~5,000 years ago whereas Rapa Nui was only settled ~1000 years ago (though more likely it seems no earlier than 1200 CE or 800 years ago). It's just very hard to believe that the Harrapan writing system could have somehow survived and travelled across the Pacific without influencing any other culture or leaving behind any other writing system. There are petroglyphs; that is glyphs that could be the precursor to writing systems across parts of the Pacific; there are a number of them in Hawaii for instance, but they represent no formal system of writing and existed more like memory aides that abstract representations of concrete ideas that could be read.
The theory that these could be connected- Harrapan civilization and Polynesia; used to be very popular at the end of the nineteenth century and first part of the twentieth; scholars like Sir Peter Buck, imagined the Polynesians being part of this great migration from Egypt or India and into the Pacific. This theory was popular for several reasons; on the one hand its very romantic and gives human history a very grand feeling; two, it helped justify and explain why Polynesians were racially on a similar level to white Europeans- the story linking them to a lost white civilization (or near white at any rate), helped explain why they were so advanced, and helped justify the racial ordering given to the Pacific by explorers like Dumont d'Urville. As archeology has explored more of the Pacific since the Second World War, it has become clear that the grand migration theories have little basis in fact and that the Pacific was not settled in one grand wave several thousand years ago; but instead gradually over the course of five thousand years in leaps, jumps, and pauses. It has also become more apparent that the Polynesians were not some distinct people that entered into the Pacific; but are linked with the other peoples of the Pacific in common heritage.
It is also possible, that the Rangorango script was only invented after contact with Europeans, and was not a writing system at all, but an imitation of a writing system- perhaps because someone or some group on Rapa Nui saw European writing and believed it held some spiritual power and they wanted a way to access that power themselves (sort of like the Cargo cults that would appear in various parts of the Pacific later on). This has appeared a pretty convincing argument when one considers some of the signs in the rangorango script clearly represent animals and objects of European origin; or things that were brought to the island only after European contact. It is also possible the script was invented to sell to European ethnologists who came to Rapa Nui looking for cultural secrets. Some peoples in New Guinea were known to do this, taking advantage of European curiosity and demands for unique cultural information, to sell them made up stuff or invented traditions. The fact that the script only appears after Euro-Americans start asking for it would seem to indicate this as a possibility- because none of the earlier explorers or traders who stopped at Rapa Nui mention a local script of any kind.
Some further reading if you are interested....
On Easter Island itself and its settlement
On the settlement of the Pacific
On these kinds of myths and legends
One of the writers of the grand migration theories; which is very interesting and fun to read; but we must always be careful to remember the context in which it was written and the racially charged scholarship it represents.