Union Government
(1) After grants are made under Article 113, an Appropriation Bill is introduced to authorise withdrawal from the Consolidated Fund of money for those grants plus charged expenditure (not exceeding the amounts shown earlier). (2) No amendment may be proposed to such a Bill that would vary a grant's amount/destination or alter charged expenditure; the presiding officer's ruling on this is final. (3) Subject to Articles 115-116, no money can be withdrawn from the Consolidated Fund except under an appropriation made by law under this article.
Once the Lok Sabha approves specific spending "demands", a separate Appropriation Bill is passed to formally authorise actually withdrawing that money from the government's Consolidated Fund - this Bill can't be amended to change the amounts already approved, it just legally formalises the earlier grant decisions.
This is why the Union Budget process has two distinct legislative steps: first the Lok Sabha votes on individual "demands for grants" by ministry, then a single Appropriation Bill is passed to legally authorise the government to actually spend that already-approved money.