My mother suffering with a problem of chronic amebiasis and her age is 50yrs, she is under tmt with Flagyl and ofloxacin with tindiazole, hw long threpy?

Depends. Duration of therapy depends on the severity, chronicity of the disease in the particular patient. Recommended durations of treatment also vary between practitioners. If disease relapses after meds discontinued, repeat treatment may be needed.
About 5 -10 days. Metronidazole or tinidazole are generally used for about a 5 day course to eliminate tissue infection, often followed by paromomycin or diloxanide to treat the intestinal form of the parasite. Do not know why she is getting ofloxacin, unless more than one infection.