The yearly charge, even if you do not sell
A foreign fund owes a small tax every year even if you never sell it, and that catches German residents out. Under Germany's investment-tax rules, this annual advance charge is called the Vorabpauschale. It is a small deemed return, computed from the fund's value at the start of the year multiplied by a set base rate, currently modest, and capped at the fund's actual rise in value for the year. You are taxed on that advance amount at the flat 25% plus surcharge, even on an accumulating fund that distributes nothing and even though you have not sold anything.
Equity funds soften this: a 30% partial exemption applies to the advance charge, to distributions and to the eventual sale gain, so only 70% of each is taxed. The point to take away is that an Indian fund is not fully tax-deferred for a German resident, you pay a little each year. It is much milder than the American regime that penalises foreign funds, but it is not nothing, and it needs reporting annually.
When you sell, the German side
When you finally redeem, the gain is taxed at the same flat rate, again with the 30% partial exemption for an equity fund. Crucially, the advance charges you already paid over the years are deducted from the sale gain, so you are not taxed twice on the same growth. So the yearly charges are, in effect, prepayments against the final bill.
Is the gain taxable in India? The DTAA and Article 13
India taxes the redemption in its own right: equity fund long-term gains over ₹1.25 lakh at 12.5%, short-term at 20%, and debt funds at your slab rate, with the fund house deducting TDS. But the India-Germany treaty decides who actually gets to tax the gain, and it splits capital gains by the type of asset. Article 13(4) lets India tax gains on shares of an Indian company. Article 13(5), the residual clause, gives the sole right to tax any other property to your country of residence, Germany. Indian mutual fund units are not shares: a fund is a SEBI trust and a unit is issued by the trust, not by a company, so the argument runs that a fund-unit gain falls under Article 13(5), taxable only in Germany and not in India.
So you recover the fund house's TDS as a refund. You file an Indian return, ITR-2, taking the Article 13(5) position, with your German tax-residence certificate (the Ansässigkeitsbescheinigung) and Form 41, formerly Form 10F, and reclaim the tax the fund deducted under Section 393(2), the old Section 195. This rests on the tribunal view that fund units are not shares rather than on settled statute, and on your being a genuine German resident, so keep the residence certificate and paperwork clean.