Nanocrystalline cellulose has achieved researchers' attention due to its exceptional physical and biological characteristics, including its large surface area, biodegradability, biocompatibility, and low toxicity. In India, agricultural waste is usually dumped in landfill, and agricultural waste burning is also considered the most effective and efficient way of clearing landfills. This fire is the largest carbon black source, threatening the environment and humans. Utilization and conversion of this agricultural waste help in protecting the environment. In the past few decades, researchers have focused on isolating NCC from agricultural waste. The present work focuses on examining the disintegration potential of sugarcane bagasse nanocrystalline cellulose (SCBNCC), banana peel nanocrystalline cellulose (BPNCC) prepared from sugarcane bagasse derived microcrystalline cellulose (SCBMCC), and banana peel powder (BPP), respectively. Further, the concentration of SCBNCC and BPNCC as a disintegrant was optimized for the preparation of Diclofenac potassium IR tablets using quality by design (QbD). Diclofenac potassium is used as the model drug for the study. The direct compression method was used for the preparation of tablets. The optimized tablet was characterized by various evaluation parameters as per USP. The quality target product profile (QTPP) was defined along with critical attributes of the formulation. Disintegrant concentration and compression force were used as independent variables. A full factorial design 2-factor at 3-levels was used to optimize disintegrant concentration (individually for SCBNCC and BPNCC). Checkpoint analysis was carried out to validate the regression model's reproducibility. The disintegration time (DT) obtained for the tablets was 313 \& PLUSMN; 0.63 s (SCBNCC used as disintegrant) and 342 \& PLUSMN; 0.75 s (BPNCC used as disintegrant). The novel disintegrant used for the oral formulation showed promising results and can be explored as an emerging disintegrant for solid oral dosage form.