ITR 1 filed under old regime but defective notice received

Uday venkat (Accountant) (51 Points)

28 September 2024  

my client is having salaried income and 194 IB ( rental income from plant and machinery) income,

ITR 1 have been filed and shown rental inccome as IFOS, original return filed before due date but now due to defective notice, we need to show rental income under PGBP (technically Form 10 IEA has not been filed as we filed ITR 1) now we need to file ITR 3 or ITR 4 but only under NEW REGIME

 we have refund of 90k (if we change regime  in the same FY  i heard refund will not be processed),please suggest 

we have given response to the defective notice but no reply from dept yet (its been 1 month)