We present PARAMANU (which means "atom" in multiple Indian languages), a family of novel language models for Indian languages. It is a collection of auto-regressive monolingual, bilingual, and multilingual Indian language models pretrained from scratch, currently covering 10 Indian languages (Assamese, Bangla, Hindi, Konkani, Maithili, Marathi, Odia, Sanskrit, Tamil, Telugu) across 5 scripts (Bangla, Devanagari, Odia, Tamil, Telugu). The models are pretrained with a context size of 1024 on a single GPU, and are of varying sizes ranging from 13.29,M to 367.5,M parameters. We proposed a RoPE embedding scaling method that enables us to pretrain language models from scratch at larger sequence length context size on single GPU without increased GPU memory. We have also developed an efficient and advanced novel tokenizer with least fertility score among existing LLMs for Indian languages using a combination of BPE and Unigram that can also tokenize unseen languages written in the same script or the Roman script. We also proposed language specific tokenization for multilingual models and domain specific tokenization for monolingual language models. In order to avoid the "curse of multi-linguality" in our multilingual "mParamanu" model, we pretrained on comparable corpora by typological grouping using the same script. We proposed and performed pretraining for more than 1 epoch of training for most of our language models. From our results, we observed the language transfer phenomenon from low resource to high resource within languages of the same script and typology. We performed human evaluation of our pretrained models for open end text generation on grammar, coherence, creativity, and factuality metrics for several languages. Our Paramanu models outperformed standard and multilingual large language models (LLMs) by a large margin in performance despite being smaller in size by 64 to 20 times. We studied the impact of language specific tokenization versus language agnostic tokenization for bilingual language modeling. We also studied the impact of BPE versus Unigram tokenization for Devanagari script languages. We further created instruction-tuning datasets and instruction-tuned our pretrained models on 23,000 instructions in respective languages except Hindi, for which we used 75,000 instructions. Comparison with multilingual LLMs on various commonsense reasoning benchmarks for natural language understanding, natural language inference, and machine reading comprehension shows the advantage of our models. The performance of our Paramanu models leads to the conclusion that high quality generative language models are possible without high amount of compute power (FLOPS) and enormous number of parameters.