Two of my favourite sci-fi books have Hindu motifs. In Lord of Light, this motif is explicit, almost lurid, reflecting the ultimately cynical way in which that polytheist religion is used in the novel. In Feersum Endjinn, the references are much more muted, and portray a much more benign interpretation of Hinduism.
Both novels deal with post-humans in the far future. Both touch upon how technology can facilitate all our human desires, (and in certain conditions) consequentially warping and distorting the morality and purpose of life of these transcendents.
In Feersum Endjinn, the melding of man and machine is very advanced, compared to Lord of Light. The latter was authored during the mid 60s, and while the sci-fi is slightly rusty around the edges (supposedly futuristic planes that make a lot of noise and light-shows), it's still a really convincing depiction of a futuristic human society. Feersum Endjinn was a lot more recent, and contains a lot of currently popular sci-fi memes, like AIs and even a version of The Matrix.
In Lord of Light, the Hindu motif is mainly used to emphasize that any system, no matter how orderly and supposedly beneficent, will be corrupted by those who hunger for power and are eager to maintain their position on top of the ant hill. The best part of Lord of Light is probably the Christian fundamentalist character who rages against the polytheist system by using his special power: raising zombies. Ahhh, Nirriti the Black, good night, sweet prince. In Feersum Endjinn, the Hindu-ish AI systems are unambiguously the good guys, concerned for the well being of the hopelessly obsolete (although technologically enhanced) humans, outclassing all the schemings of the ruling elite almost effortlessly.
Lord of Light uses a writing style that is very aggrandized, very similar to how the Mahabarata or Rig Veda is supposed to sound, I guess (I never read them). Initially the effect is kind of snobbish, poncy, but then Zelazny starts cracking jokes, and that really works. Feersum Endjinn is written in the usual Iain Banks fashion - except for one character: he yooses sumthing laik an aprowpreeayshun ov leet speek, or meibee eckstreem fonayteeshizum. The effect is bewildering at first, and the rest of the time it is kind of a hard slog to get through, but you get a certain satisfaction for going through this chav's chapters, kind of like a medal of honor for decoding enemy code.
God, that was a ramble.