TDS will when start

TDS is applicable to as assessee having income from Business or profession and who was subject to audit u/s 44AB (Tax Audit) in the preceeding financial year. Even if his income was not audited u/s 44AB in the previous year and has to get his income for the current year u/s 44AB then also TDS has to be deducted and remitted right from the first month in current finacial year. 

Yes TDS has to be deducted and remitted monthly for all expenses. Due date for remittance is 7th of subsequent all months, except for march alone its 30th of April. Return has to be filed quarterly and due date for return is 15th day from end of the quarter that is 15th July, 15th October, 15th January and for  Quarter 4 alone its 31st May. Except, for salary expense alone TDS can be deducted and remitted even at once, say for example only in March month for whole year. 

Dear jeeva
TDS due dates of F/Y 2018-19 for return filling

1st Quarter
1st April to 30th June. 31st July
2nd Quarter
1st July to 30th September. 31st Oct
3rd Quarter
1st October to 31st December 31st Jan
4th Quarter
1st January to 31st March. 31st May

Note: TDS Deducted under section 194IA on the transaction in the month of March, has to be deposited on or before 30th April of 2019.

The TDS on Salary is required to bededucted on the basis of average rate of income tax of the taxpayer for that financial year.