Hello Raghuram Kaligotla,
Welcome to Microsoft Q&A! Thanks for posting the question.
The limit of 150 fields per dataset in custom generative AI models is a hard restriction and cannot currently be increased. To address this, you can split your dataset into smaller subsets based on field groups or document templates and create separate models for each subset. By consolidating or removing non-essential fields can also help reduce the field count.
I hope you understand, do let us know if you any further queries.
Thank you!