Why is "to do" replaced by "for doing" in Indian English?

What you've observed is a specific characteristic of English in India. Briefly, the progressive aspect is overused. A summary analysis is this:

One of the most indicative signs of Indian English grammar is the use of the progressive aspect with habitual actions, completed actions, and stative verbs. This produces sentences such as "I am doing it often" rather than "I do it often"; "Where are you coming from?" instead of "Where have you come from?"; "and "She was having many sarees" rather than "She had many sarees" (Trudgill & Hannah, p. 132).

(From "LANGUAGE IN INDIA: Strength for Today and Bright Hope for Tomorrow", Volume 2 : 4 June-July 2002)

For a more complete analysis, including an investigation into possible root causes and the development of the characteristic progressive aspect use, see '"Are you wanting a cup of coffee?": Overuse of the progressive aspect in Indian English', and especially Section 6, which is introduced by these summary hypotheses:

Most linguistic changes have multiple causes (Thomason 2001: 62). It is likely that the Indian overuse of the progressive cannot be traced back to one single source; instead, several factors might work together. The following section will review three major hypotheses. Following Hansen et al. (1996: 221) and Platt et al. (1984), the overuse of the progressive can thus can be attributed to

1. processes at work in any language contact situation, i.e. transfer and/or universal processes of simplification and overgeneralization (a debate lead in the field of language contact studies and second language acquisition) or
2. certain methods and techniques in language instruction (resulting in "overteaching" of grammatical structures) or
3. a particular linguistic input that was typical in colonial situations, i.e. the influence of certain dialects and non-standard varieties of British English in the early stages of acquisition of English on the Indian subcontinent.

The analysis in Section 6 runs to 23 double-spaced pages.